For this hack, you’ll need some kind of mnemonic skeleton that can contain about 10 items (or as many as are on your checklist). You can use a short journey [Hack #3], the 10 digits of the Dominic System [Hack #6], the number shape system [Hack #2], or anything else that you can remember effortlessly and when distracted. I use the first mnemonic system I ever learned, the number rhyme system, which my father taught me when I was a boy: “One is gun; two is shoe; three is tree,” and so on. Ergo, for the first item on my list, I create a vivid image that contains the item and a gun; I remember the second item by associating it with a shoe; and so on down the list.

Compile your checklist and write the items next to the mnemonic skeleton. Put your most important items first in the list so that you’ll remember to grab those even if you are interrupted and can’t run through your entire list.

As always, link the objects you want to remember to the places in the mnemonic skeleton using the most vivid images you can. Here is my actual list:

I can honestly say that in the year or two I have been using this technique, I have forgotten particular items on the list only once or twice, and that was merely because I didn’t run through the whole list as I was packing up. There was, however, one incident, where my wife and I were late because I set my fully packed bag down momentarily and forgot to bring the whole kit with me!

I’m now so familiar with my list that 10 brings pen to mind immediately rather than hen, and so on. Therefore, it’s been easy to add two more items without thinking of additional mnemonics for them: 11, my exoself [Hack #17], and 12, a good book to read. However, if I were going to extend my checklist any more, I would certainly add more mnemonic pegs.

Table 1-1 lists 10 digits, along with some shapes you can use to remember them. The Shape column illustrates the italic words in the Words column, to show how the associations arose.

Table 1-1. Corresponding numbers, words, and shapes

Number	Words	Shape
0	Black hole, donut, tire
1	Candle, pencil
2	Swan
3	Butterfly, heart
4	Sailboat
5	Hook, pulley
6	Golf club, lasso, pipe
7	Axe, boomerang, scythe
8	Hourglass, snowman
9	Flag, tadpole

Feel free to pick and choose, or devise your own shapes. It’s most important to be consistent so that when you want to remember what you associated with the number 6, you don’t waste time trying to remember whether your mnemonic shape is a pipe, a lasso, a golf club, or something totally different.

Like the brains of all animals, the human brain has a lot more experience with concrete shapes than with abstract numbers. For example, the decimal digit 0 was not even discovered until about 300 BC.² Our ancestors used their senses to learn more about the world, find food, escape predators, and perform many other essential tasks. These tasks were vital to our survival in an evolutionary sense, so the faculties involved in processing sensory information were well developed, and today our brains still process this kind of information thoroughly and efficiently.

Thus, by turning numbers into concrete shapes and making them even more imaginably vivid with motion, humor, sex, aggression, color, smell, touch, taste, and all the other features of the real world that our primate brains evolved to process, we’re in effect wrapping the numbers with mental friction tape so that we can grasp them better.

Of course, it’s possible to become intimately familiar with numbers in their own right [Hack #36], and doing so will help you not only to remember them, but also to get better at math.

Here is how you might use the number shape system to remember a list of five items to pick up at an office supply store. As is often the case with image-based memory systems, the more vivid the mental image you can conjure, the easier it will be for you to remember.

I often use the number shape system to make a quick shopping list when I have to grab some groceries on the way home. If you learn this system, you’ll probably develop many applications of your own, such as taking notes on the points you need to address when it’s your turn to speak in a meeting.

When you create your mental images, make the impressions of the objects you want to remember as vivid as possible, to make the ideas you want to remember stick to the places of your journey. You can do this in many ways, such as by exaggerating them or using humor, sex, bright colors, motion, or anything else that holds your attention. (The word impression comes from yet another classical metaphor depicting memories as the marks left by a stylus on a wax tablet, the yellow legal pad of the day. When you make impressions on the wax tablet of your mind, press down hard.²)

To assemble your first memory journey, use a place you know extremely well; your home is a good example. You can also use the shops along a street where you walk every day or the benches, brooks, and shady trees of your favorite park. Just make sure you can trace your journey from beginning to end in your mind’s eye before you try to use it as a mnemonic tool.

After you memorize one list of objects with your journey, you can “wipe the wax clean” and reuse the journey by mentally walking its length and visualizing the places as being empty of the objects you memorized. Blow up the objects with dynamite if you like.

You might want to create multiple journeys of different lengths, so you have one ready for any occasion. Then, if you need a journey longer than any you have memorized, you can link two or more journeys together by starting one where the last ended; imaginary journeys don’t need to obey real-world geography.

Here are the first 10 places on my first journey, with typical actions envisioned for each. This journey is based on my real-life apartment. Places 1–5 start on the right side of the apartment (as seen from the start of the journey). After place 5 (the porch), the journey makes a left turn into the living room and doubles back so that places 1–10 make a horseshoe shape.

When I was reading the “Famous Forty” Oz books, starting with The Wonderful Wizard of Oz and running through the next 39 canonical books in the series, I used pegs 1–40 of the Dominic System [Hack #6] to memorize their titles. Let’s use my apartment journey to memorize the titles of Shakespeare’s 10 tragedies:

Notice that I used images to remind me of specific words in the titles of the plays. Since I’m already familiar with the play titles, this should be enough to remind me of them. If you don’t already have a rough idea of the things you’re trying to memorize, you might need to make more detailed images that are less ambiguous, or piggyback another memory technique onto this one.

The images need not have a logical connection with the mental location where you place them, since the places in the journey are essentially arbitrary, just like the pegs in the number rhyme system [Hack #1]. For example, I don’t have a Macintosh in my kitchen sink, nor would I ever put one there. Actually, that very fact makes the placement of an imaginary Mac there all the more memorable. Absurdity is one of the many techniques used to make images vivid.

If you want to remember more play titles, simply add more places to the journey. For example, place 11 could be my car and could hold the first Shakespearean comedy, The Comedy of Errors. I could open my car door outside and find that the controls on my dashboard are backward and upside down, which makes me laugh.

Imaginary journeys can be extended indefinitely, so after you memorize all of Shakespeare’s plays, you can move on to the works of other authors, or anything else you want to remember.

Scott Hagwood, the U.S. Grandmaster of Memory, seems to have invented the nooks-and-crannies hack. He used it to break the world record for color-sequence memorization for the electronic game Simon. The previous record had been 14 sequences, but Scott was able to play an astonishing 31 sequences—all that the machine could offer. To do so, he used a memory journey and mentally stuffed the corners and walls of his places with items representing the colors he was trying to remember, such as a yellow sun or green bouncy balls.

Reconstructing Hagwood’s system from his interviews is simple enough.^2,3 Hagwood’s map for each room looks something like Figure 1-1.

Figure 1-1. The nooks and crannies of Hagwood’s memory journey

The map in Figure 1-1 assigns numbers to the following places:

While this might not be Hagwood’s exact system, it’s the one we’ll use in this hack.

In “Make Lots of Little Journeys” [Hack #3], we used a memory journey to recall Shakespeare’s tragedies. Suppose you want to store more information about the plays in the same journey. You might associate the features of the plays with the features of the rooms in your memory journey in this way:

You can think of the floor and the ceiling as special places within the room, so you can use them for special information about the play—in this case, the publication date and a related work. (The other eight places are all the same: slots for plot elements.) If you were memorizing the periodic table of elements, you might use the floor and ceiling for two key pieces of information: the alphabetic symbol of the element (such as Au for gold), and its atomic number (79). The rest of the places could then be used for other details.

Let’s try the nooks-and-crannies hack to memorize the details of Shakespeare’s second tragedy, Romeo and Juliet. In “Make Lots of Little Journeys” [Hack #3], I associated this play with the back bathroom of my apartment. Now I will associate the features of the play with the features of this room, in detail:

The mnemonic for the publication date is worked out using the Dominic System [Hack #6]. The plot events should not be hard to visualize if you’ve seen the play; otherwise, you can use mnemonic tricks, such as representing Paris with a miniature Eiffel Tower, Mercutio with winged sandals like those of the god Mercury, and so on.

You can use the nooks-and-crannies hack to memorize any information that can be presented serially, from the digits of π, to the telephone area codes of the U.S. and Canada, to the nations of the world in alphabetical order. And if all of these examples leave you unimpressed, does the word Vegas suggest anything more to your taste?

The Major System uses peg words just like the number-rhyme system [Hack #1] and number-shape system [Hack #2]. Instead of associating numbers with peg words based on rhymes or shapes, however, it assigns each digit a basic consonantal sound and builds up peg words from combinations of those consonants. For example, the digit 3 is linked to the consonant M, and the digit 2 is linked to the consonant N, so our Major System list suggests moon for 32.

The consonant assignments are fairly arbitrary—Lewis Carroll came up with an alternate set [Hack #9] that’s probably just as good—but Table 1-2 shows a standard set of mnemonics you can use for these associations until they become second nature.

Table 1-3 shows the Major System peg word list for the numbers 1 to 100. If you don’t like the words I use, you can use your own. Since your list will use your own mental connections, it might be even more effective for you. Just be consistent, so you don’t have to grope to remember the peg word for a particular number.

When you’re converting numbers to peg words and back, there are some simple rules to follow:

Since there are only a limited number of possible words in English for each number, the mnemonic lists for the Major System in most memory books tend to be similar. I consulted three of the books in my collection^2,3,4 to compile this list, taking the best from each and adding my own words (such as 42 = RaDio and 81 = VaT) when it seemed useful. I followed several guidelines, which might interest you if you want to customize it:

If you have a credit card with the number 4880 6630 6767 7584 (these digits were generated at random with the dice-rolling application on my PDA), you might remember them with the words shown in Table 1-4.

But now you have a new problem: how are you going to remember this arbitrary list of words, especially the two sequential instances of chalk?

You can use the following little story—a kind of memory journey [Hack #3]—to string them together:

A shingle falls off your roof and breaks a vase. A choo-choo of the sort in a kiddie amusement park chugs up and the conductor gets out. He’s a moose! He scolds you and tries to write you up with a piece of chalk, but his slate is also made of chalk. (How weird.) He bellows in frustration and begins shoveling coal to leave, but he gets sooty, and abashedly asks you to brush out his fur.

With just a few mental rehearsals of this story (or the equivalent for your own card), you just might never forget your credit card number again. If you actually recall the number a few times in the bustle of real life, you’ll begin to remember the number directly and let the story fade naturally.

The Dominic System uses an easy-to-remember number-to-letter conversion and the initials of memorable people, as well as journeys that are like memory palaces [Hack #3]. As many mnemonic systems do, the Dominic System requires some bootstrapping for you to reach its full potential.

You will have to spend a little time and work to memorize the structure of the system, and that might seem a little tedious. Your work will be rewarded, however, because this basic work will enable you to harness the system’s full power for yourself. It’s a little like starting slow on the treadmill at the gym if you want to work up to taking long hikes in the mountains.

The number-to-letter correspondences run as follows:¹

You can remember the numbers 00 to 99 by linking them to famous people and actions that are characteristic of them. For example, the number 15 becomes AE. You might mentally connect the initials AE with Albert Einstein and assign writing on a blackboard as Einstein’s characteristic action. Similarly, 80 = HO = Santa Claus, laughing and holding his belly (HO, HO, HO!). You can use my list² or O’Brien’s list, but the system will work best if you use the associations that are already in your own mind.³

After you have the two-digit associations firmly in your mind, you can remember four-digit numbers by combining the person associated with the first two digits and the action associated with the second two digits. Thus, 8015 can translate to HOAE, which can be broken down to HO and AE. To remember it, think of Santa Claus (HO) with Albert Einstein’s action (AE): Santa Claus writing on a blackboard.

You can remember five-digit numbers by adding a symbol from the number-shape system [Hack #2] to the image, so that 80152 might be represented by Santa writing on a blackboard with a swan (2) tucked under one arm. You can remember longer sequences of numbers (such as memorizing the digits of π), or sequences of any kind, by chunking them [Hack #11] and committing them to the places of a memory journey.

Here’s an example of how to memorize a 12-digit number: the month table used to calculate weekdays [Hack #43]. I will use my personal associations for the letter combinations and fill in from other sources when my own mnemonics are too idiosyncratic to make sense to most people.

First, make one long list of the month numbers. Since none of them is larger than 6, they are all one digit long, so we obtain a 12-digit number:

033614625035

Next, break up this list (i.e., chunk it) into three four-digit numbers:

0336 1462 5035

Now, apply the Dominic System mnemonics:

Next, make an imaginary journey [Hack #3] by using the first character associated with each number performing the action associated with the second character:

Oliver Cromwell (OC) steps into the magic wardrobe and ends up in the land of Narnia (CS). He wanders through the snow until he comes to the lamppost, where he meets Jesus (AD), who leaps into a bus and starts driving away like crazy (SB). Jesus doesn’t get far, however, because Eeyore (EO) appears from behind a bush and lassos him like Clint Eastwood (CE).

Did you find this little journey offensive or surreal? Strong emotional reactions help people remember things, so outlandish mental images can actually be more effective to use. Again, you should make your own list of characters for your own version of the Dominic System, and then you can tune your list to suit yourself.

The Dominic System is a combination of the innovative (easier mnemonic alphabet, using people rather than inanimate objects because people are easier to remember, etc.) and the tried-and-true (memory palaces, which go back to classical times). It has a couple of advantages over the Major System and its derivatives:

As my first test of the Dominic System, I used the subset of numbers from 01 to 40 to memorize the titles of a favorite series of books, the so-called Famous Forty by L. Frank Baum and his successors, set in the Marvelous Land of Oz. For example, book 23 is Jack Pumpkinhead of Oz. The number 23 corresponds to BC in my personal Dominic System, for which the person/action pair was Thor, the character from the comic strip B.C., riding his stone unicycle. Thus, the image I used to remember this book was Jack Pumpkinhead riding a stone unicycle.

Memorizing the titles of the Famous Forty took about 45 minutes, approximately a title a minute. A minute is about as long as it takes Dominic O’Brien to memorize an entire shuffled deck of cards, so at that point I had a lot of room for improvement. These days, I can memorize items several times faster than I could at the beginning—still not as fast as a World Memory Champion, but improving.

As it happened, I made a fruitful mistake with this test. I was already familiar with the more common Major System, and I thought that the Dominic System’s numbers from 00 to 99 were meant to be used as mnemonic pegs or places [Hack #3], just like the numbers in the Major System. In fact, the numbers are mainly used to encode numeric information; Dominic himself would probably memorize the Famous Forty with a memory journey.

I’m glad I made my initial mistake, though, because it led me to build on the Dominic System to construct the Hotel Dominic [Hack #7], which theoretically enables you to memorize 10,000 items or more of information.

You can think of the Hotel Dominic as a building with 100 floors, numbered from 00 to 99, each containing 100 rooms, also numbered from 00 to 99. In short, it’s like a grid with 100 rows and 100 columns. The first room on Floor 95 would thus be numbered 9500. The next room along the hall would be 9501, then 9502, and so on. Figure 1-2 shows the first few rooms from the bottom floors of the Hotel Dominic, starting with the first floor, Floor 00. The hotel continues both up and to the right.

Figure 1-2. A few rooms in the Hotel Dominic

If you need to memorize a list with more than 100 numbered items, allocate an empty section of the matrix to that list. For example, to memorize the periodic table of elements, you could arbitrarily allocate rooms 8001 to 8116. Room 8001 would contain information about the first element, hydrogen, and 8116 would contain information about the element with the highest known atomic number, ununhexium (element 116).¹

If you have memorized the 100 people/action pegs of the Dominic System, you already have everything you need to memorize the 10,000 rooms of the hotel. Room 8001 in the Hotel Dominic would be represented by whatever combination of person and action you have designated for HOOA. Four-digit numbers are easily memorized with the Dominic System, so all you need to do is associate hydrogen with the Dominic mnemonic for this number.²

Here’s an example of how to memorize the first element in the periodic table, hydrogen.

As mentioned in the previous section, place hydrogen in Room 8001 of the Hotel Dominic (in other words, Floor 80, Room 01). The number 80, as mentioned in “Use the Dominic System” [Hack #6], is represented by Santa Claus (80 = HO, which reminds us of Santa’s HO, HO, HO). In my personal list, 01 is that guy on the oatmeal box (01 = OA = oats), and his characteristic action is offering a bowl of oatmeal. Thus, 8001 is represented by Santa Claus offering me a bowl of oatmeal.

To link hydrogen to the picture, I imagine that the oatmeal is bubbling, and little bubbles of hydrogen gas are escaping from it and bursting into flame. It’s then easy to remember other information about the element, such as its chemical symbol, H. I visualize a shiny H on Santa’s forehead, as on the forehead of the “holographic” character Rimmer in the TV series Red Dwarf. I imagine that the shiny H reflects the flames from the exploding hydrogen bubbles, making it vivid and easier to remember.

Other features of the character, the character’s action, and the room could be used to store other information about hydrogen, such as its atomic weight (1.008) and the year it was discovered (1766), both of which are four-digit numbers and also easily encoded with the Dominic System.

It’s not as easy as playing foosball or watching a DVD, and experience shows that you’ll need to refresh your memory periodically. However, “Dominate Your Memory” [Hack #8] provides a script to print up chunks of your personal memory hotel for easy review, and if you’re studying for your chemistry exam or going on Jeopardy!, a mnemonic technique like the Hotel Dominic beats rote drill techniques and makes them cry.

Place the following Perl script in a text file called dominate:

#!/usr/bin/perl -w

$in_file = $ARGV[0];
$domstart = $ARGV[1];
$domend = $ARGV[2];

if ($domstart > $domend)
{
    die "Start number not less than or equal to end number\n";
}

open (IN_FILE, "< ./$in_file")
    or die "Couldn't open input file: $!\n";

$index = 0;
while (defined ($line = <IN_FILE>)) 
{
    $line =~ /([^;]*)\:([^;\n]*)/g;
    $domarray[$index][0] = $1;
    $domarray[$index][1] = $2;
    $index++;
}

close IN_FILE;

for ($domnum = $domstart; $domnum < = $domend; $domnum++)
{
    $domstring = sprintf "%0004.0d", $domnum;
  print "$domstring: ";
    $domstring =~ /(\d\d)(\d\d)/g;
    print "$domarray[$1][0]\,$domarray[$2][1]\n\n";
}

You will need to create your own datafile that contains your personal characters and actions that match the numbers in the Dominic System [Hack #6]. It must start with the character and action for 00 and continue through the character and action for 99. Each line must contain the character name, followed by a colon, then a space, and then the character’s typical action. Colons must be used only to separate characters and actions; they cannot appear anywhere else in the file. If your text editor has a line number feature, you can use it to keep track of where you are in the file, such as line 1, which should contain the mnemonic for 00, or line 100, which should contain the mnemonic for 99.

Here are the last 29 lines of my dominate datafile, dominic.dat, corresponding to items 71–99:

$ tail -29 dominic.dat

Ray Charles: playing piano and singing ("GeorgiA")
George W. Bush: clearing brush in Crawford, TX
Graham Chapman: throwing open windows and exposing himself (scene from _The Life of 
Brian_)
Gandhi: spinning on a wheel
General Electric (a robot in uniform): saluting
Smeagol-Gollum (_The Lord of the Rings_): falling into lava with the One Ring
Gandalf the Grey (_The Lord of the Rings_): barring the way with staff
George Harrison: tapping foot and playing guitar
Ignatius Loyola: flogging himself (iGNatius)
Santa Claus: laughing until belly shakes (HO HO HO!)
Julia Sweeney: dressing gender-ambiguously (_God Said HA!_)
Humphrey Bogart: pulling the brim of his hat low
Hagbard Celine (_Illuminatus!_): piloting golden submarine
Howard Dean: whooping
Isaac Newton (long white wig): releasing helium balloons (Newtonmas, HE HE HE!)
Homer Simpson (_The Simpsons_): gobbling donuts
Mercury (Greek god): flying with winged sandals (Hg = chemical symbol for mercury)
Hermann Hesse (author of _The Glass Bead Game_): telling beads
Han Solo (_Star Wars_): firing blaster
Dr. No: manipulating controls in his secret headquarters
Neil Armstrong: stepping onto Moon
Norman Bates: stabbing someone repeatedly
David Sedaris (author): chasing rolling coins down the street (North Carolina)
Nick Danger (Firesign Theatre, Phil Proctor): walking into a red sandstone building (oof!)
Neelix (_Star Trek_): cooking alien food
Hiro Protagonist (_Snow Crash_): cutting someone to bits with a katana (Neal Stephenson, 
author)
Morpheus (_The Sandman_): strewing sand (Neil Gaiman, author)
Nathaniel Hawthorne: tearing open his shirt to reveal a scarlet letter
Nick Nolte: falling into pool (scene from _Down and Out in Beverly Hills_)

In “Visit the Hotel Dominic” [Hack #7], I suggested memorizing the Universal Declaration of Human Rights¹ by placing it after the periodic table of elements in the Hotel Dominic. That hack placed the periodic table of elements in the hotel running from 8001 to 8170, with the 30 articles of the declaration running from rooms 8171 to 8200.

However, since Santa (80 = HO!) is easier for most people to visualize than Julia Sweeney (81 = HA!), for purposes of illustration only, we’ll place the 30 articles in rooms 8071 to 8100. (Of course, you can place them anywhere you wish.)

If you have Perl installed on your system, to print out the “inhabitants” of these 30 rooms, save the dominate script and the dominic.dat file in the same directory, and then run dominate by typing the following command within that directory. The first argument should be the name of the datafile (in this case, dominic.dat), the second argument should be the starting room (8071), and the third argument should be the ending room (8100):

perl dominate dominic.dat 8071 8100

If you’re on a Linux or Unix system, you might also be able to use the following shortcut:

./dominate dominic.dat 8071 8100

The following is a set of results from an actual dominate run:

$ ./dominate dominic.dat 8071 8100

8071: Santa Claus, playing piano and singing ("GeorgiA")
8072: Santa Claus, clearing brush in Crawford, TX
8073: Santa Claus, throwing open windows and exposing himself (scene from_The Life of Brian_)
8074: Santa Claus, spinning on a wheel
8075: Santa Claus, saluting
8076: Santa Claus, falling into lava with the One Ring
8077: Santa Claus, barring the way with staff
8078: Santa Claus, tapping foot and playing guitar
8079: Santa Claus, flogging himself (iGNatius)
8080: Santa Claus, laughing until belly shakes (HO HO HO!)
8081: Santa Claus, dressing gender-ambiguously (_God Said HA!_)
8082: Santa Claus, pulling the brim of his hat low
8083: Santa Claus, piloting golden submarine
8084: Santa Claus, whooping
8085: Santa Claus, releasing helium balloons (Newtonmas, HE HE HE!)
8086: Santa Claus, gobbling donuts
8087: Santa Claus, flying with winged sandals (Hg = chemical symbol for mercury)
8088: Santa Claus, telling beads
8089: Santa Claus, firing blaster
8090: Santa Claus, manipulating controls in his secret headquarters
8091: Santa Claus, stepping onto Moon
8092: Santa Claus, stabbing someone repeatedly
8093: Santa Claus, chasing rolling coins down the street (North Carolina)
8094: Santa Claus, walking into a red sandstone building (oof!)
8095: Santa Claus, cooking alien food
8096: Santa Claus, cutting someone to bits with a katana 
(Neal Stephenson, author)
8097: Santa Claus, strewing sand (Neil Gaiman, author)
8098: Santa Claus, tearing open his shirt to reveal a scarlet letter
8099: Santa Claus, falling into pool (scene from _Down and Out in Beverly Hills_)
8100: Julia Sweeney, knocking something over ("Oh Oh!")

Your dominate script will print a double-spaced list so that you have room to annotate it by hand.

To remember the first five articles of the Universal Declaration of Human Rights, you might annotate them as follows, with a detailed visualization and a paraphrase of the relevant article:

First, you need to memorize the number-to-consonant conversions shown in Table 1-5, which provides mnemonics for remembering the mnemonics.

The next step is to convert the numbers you are trying to remember to a word or words and to make them the last part of a rhyming couplet. Carroll gives the following example to remember 1492, the year Columbus first came to America.

First, drop the 1 from 1492; it’s obvious Columbus didn’t sail in 492 or 2492.

Next, convert 492 to a word using either of the pair of letters associated with each digit, like this:

As it happens, the letters in the second row (FND) will form the word found nicely, but some other combination might have been used, such as QND for queened (as in “The pawn was queened when it reached the eighth row”).

Carroll writes:

The poetic faculty must now be brought into play, and the following couplet will soon be evolved:—

“Columbus sailed the world around,

Until America was F O U N D.”¹

Presto! Convert FOUND back to FND by extracting the vowels; then convert that to 492, and you have it.

Carroll makes remembering numbers with rhyming couplets seem as easy as falling off a bicycle (they say you never forget how). But Carroll was an Oxford don, a mathematician, and a gifted poet. How easy is it for us to “bring our poetic faculties into play?”

I will now demonstrate the use of the method to remember the phone numbers of Powell’s City of Books in Portland, Oregon (my favorite bookstore; visit it if you get a chance) and the Seattle branch of Ikea (where I do have to go periodically).

The phone number for Powell’s City of Books is (800) 878-7323. We’ll drop the toll-free 800 area code as being obvious, just as Carroll did with the 1 in 1492. That leaves 878-7323. Using the mnemonics shown in Table 1-5, we can convert the phone number to letters, like this:

From these pairs of letters, we choose seven consonants that can form words:

H M K M T W T

And then the words themselves:

HAMMOCK MY TWIT

Note that I’m treating MM as a single 7 and CK as just K. I learned this consonant-melding trick from the Major System [Hack #5]; Carroll doesn’t mention it. If you really do have a number with a double digit, such as 77 (MM), in it, either put a vowel between the consonants you use (as with MOM) or use two separate consonants (such as MP, as in lump).

Also, note that I had half an idea of what the final rhyme would look like when I selected the letters; as soon as I saw HMK, I thought of myself coming home from Powell’s with an armload of books and lying down in a hammock to read them. The final result?

Now, for the Ikea Seattle store, whose phone number is (425) 656-2980. Again, I can omit the area code, because I know where the store is and what its area code is likely to be. That leaves me with 656-2980. Again, using the mnemonics shown in Table 1-5, we can convert to letters, as shown here:

From these pairs of letters, I select:

S V S W N K R

SAVES A WANKER

I thought about rhyming wanker with tanker, anchor, and Angkor—all suggestive of the global reach of Inter IKEA Systems BV—but all the couplets I came up with were too long. Eventually, though, I devised this ditty:

Rude, eh? Don’t worry; that makes it easier to remember.

Neither of these two rhymes took longer than a few minutes to create. However, they have stuck in my memory, suggesting that you use this method for data that’s important to you, that you want to retain, and that you don’t mind spending a little time learning. Carroll himself used his system to remember dates associated with various Oxford colleges, among other things; he would trot out the dates when showing guests around Oxford. Apparently, he used it to memorize logarithms as well.

A similar principle is at work in the mnemonic parody technique [Hack #10], which you can use to remember many more kinds of information than numbers.

To write a parody, begin with a topic you want to remember. Next, choose a popular song you know well and remember easily, or one that sounds like a word in your topic. This is best if you can transform the original lyrics into lyrics about your topic by changing only a few choice words. For example, if you’re writing a song about baboons, pick an original song about a balloon, saloon, or something else that rhymes. How about “Up, up, and away, with my beautiful baboon”? Making humorous or absurd mental images makes things easier to remember, and when you’re writing something funny, writing is a lot more fun. Often, once you start, the lyrics fall into place and you’re laughing as you think of the next line. Continue working your information or story into the song until you get everything in, adding more verses if necessary.

Writing a story song to an original tune takes a certain kind of talent that the average person may or may not feel comfortable with. It’s perfectly OK to use a traditional song here; it’s also fine if your original melody isn’t award-worthy, as long as you can remember it. If you choose a folk tune, you can either use the original lyrics as a base, as you would with a parody, or write your own from scratch. If you are using an original tune, you will have no base lyrics to work from, but coming up with your own lyrics can be half the fun. It can also make the memory stronger if you take time to craft all of the lyrics. Take the time to make it rhyme, too; rhyme and meter (meter is the rhythm of the words, as in poetry) are important to any song and will certainly help embed it into your mind. (Compare Lewis Carroll’s couplets [Hack #9], which use a similar principle.)

List songs are often the easiest to compose. First, write out a list of information you’d like to memorize. This will give you a ready list when you need to pick the right word to rhyme or fit the meter. Next, find a tune that has either verses or repetitive sections you can repeat enough times to include your entire list. Start to sing the tune for your chosen song, and instead of the words, sing the list. You will probably have to add connecting words here and there and maybe at the end of lines to help the rhyme. If you can make the words on your list fit into the rhyme, however, it’s more powerful. Making the list alphabetical can help you remember what comes next in the song. This works especially well if you have at least one word on your list for most letters of the alphabet (if not every one), such as the names of the states. You can also group information by geography (if you’re memorizing countries in Africa, for example) or any other way that makes sense; this will aid your memory, too.

In all cases, physically writing or typing your work will help stick the information in your mind. Also, the more familiar your framework song or poem is, the easier it will be to remember its new words.

Parodies are particularly effective for remembering a group of related information or a story. The following parody, written by teenage girls, is not a mnemonic, but it’s a good example of how to write a parody. “Negligee” is the story of a woman who buys an unfortunate piece of lingerie. It uses the tune to the Beatles’ “Yesterday.”

If you were a child with access to a television in the ’70s or ’80s, you are probably familiar with Schoolhouse Rock. The producers of these animated shorts, which were shown between cartoons on network TV Saturday morning programming, knew well the teaching power of story songs. These songs, with accompanying animation, taught science, math, history, and English language skills to original catchy tunes, from “Conjunction Junction” to “My Hero Zero” to “The Preamble” (which set the preamble of the United States Constitution to music). Many other children’s TV shows have also used this technique, notably Sesame Street; its efficacy is well documented.

The contemporary band They Might Be Giants have recorded many story songs that teach topics including mammals, James K. Polk (the 11th president of the United States), and the sun. Their most recent contribution is an album to help kids learn the alphabet, called Here Come the ABCs. There are songs about the letters themselves, such as “E Eats Everything,” and songs about the alphabet in general, such as “Alphabet of Nations” and “Who Put the Alphabet in Alphabetical Order?”

The following example was recorded by They Might Be Giants and released as a single. Both of the core members of this band learned this song as kids from an album put out by Singing Science Records and remembered it all through their lives. When they discovered they both knew it, they wanted to record and perform it. It was an underground hit. These are the first few lines from “Why Does the Sun Shine?”:

List songs have been recorded by many artists over the years, but all serve a similar purpose: to remember a long list that would otherwise be nearly impossible. List songs exist for memorizing the names of all the countries on Earth, the states of the U.S. and their capitals, and even the chemical elements. In “The Elements,” comedian and MIT professor Tom Lehrer cheerily lists every name on the periodic table of elements to the tune of “I Am the Very Model of a Modern Major-General” from Gilbert and Sullivan’s The Pirates of Penzance. Much like memorizing the digits of π, memorizing “The Elements” is a geek rite of passage.

Probably inspired by this, I wrote a song as a freshman in high school to teach my science class about the alkaline and alkali earth metals from the periodic table. Using little facts I found during my research, I wove them into the lyrics, sung to the tune of "Yankee Doodle.” That was more than 15 years ago, and I can still remember it:

Meredith Hale

Here are 40 random binary digits. Examine them and spend as much time as you want memorizing them, then look away from this book and try to write them down. The only rule is that you may not convert them to another base, count them, restructure them, or use any other mnemonic trick to memorize them. You must memorize them by rote as you see them on the page. Are you ready? Go!

0011110111110111111100000010000010000011

How did you do? Probably not too well. If you did well, either you’re a mutant with frontal lobes the size of a soccer ball, or you couldn’t help but notice (for example) that the third group of 1s is seven bits long and is followed by six zeroes, then a 1 with five zeroes, and another 1 with five zeroes. In other words, you chunked them, you cheater!

Now, assuming you understand how to convert between binary (base two) and decimal [Hack #40], you can group these bits into bytes to produce five groups of eight bits, which you can recode to five decimal numbers, like this:

00111101  11110111  11110000  00100000  10000011
      61       247       240        32       131

Look away from the book again. Try to write down the five decimal numbers and then convert them to their original binary form. Go!

How did you do at remembering the binary numbers? Probably better this time. While writing this hack, I noticed that I was spontaneously able to recall all five decimal numbers hours later without any formal mnemonic tricks. Chunking is simply a superior way for humans to process data! Miller writes:

It is a little dramatic to watch a person get 40 binary digits in a row and then repeat them back without error. However, if you think of this merely as a mnemonic trick for exceeding the memory span, you will miss the important point that is implicit in nearly all such mnemonic devices. The point is that recoding is an extremely powerful weapon for increasing the amount of information that we can deal with. In one form or another, we use recoding constantly in our daily behavior; the kind of linguistic recoding that people do seems to me to be the very lifeblood of the thought processes.

Chunking is certainly central to many mnemonic hacks in this book, such as the Dominic System [Hack #6].

The basis for the whole hack is recoding many small items that are difficult to distinguish (such as 40 bits) into a few distinct items (such as five decimal numbers). Five decimal numbers, even if they are not immediately meaningful to you, are few enough to retain in short-term memory. If some of them are meaningful to you, so much the better.

Rest assured that the technique applies to many phenomena other than binary numbers. Suppose you had a big pile of Scrabble tiles to memorize—say, 200 or so. If you could form them into words first, and then form the words into a sentence or paragraph, you’d have a much better chance of remembering the letters on the tiles.

When I was a broke psychology student, I often participated as a guinea pig in experiments at the Yale psychology and linguistics labs to earn pocket money. I had a few memorable experiences.

One experiment was designed to test the capacity of human short-term memory. A computer would flash strings of decimal digits rapidly on the screen, and the subject was supposed to type as many as she could back in. Although this was before I had made any serious study of mnemonic techniques, I instinctively chunked the digits into groups of two and three, effectively into numbers that I had made friends with [Hack #36]. I was able to beat the magic number of seven by about a factor of two without breaking a mental sweat. The experimenters seemed surprised and questioned me closely, apparently to determine whether duplicity was involved. I told them what I was doing, and they visibly relaxed; obviously, they knew about chunking, but apparently no one else who had participated in the experiment had used it.

When people fall into a tip-of-the-tongue state, they commonly focus on the few relevant things that they can remember, hoping that the elusive fact will pop into their mind after the effort of increased concentration. A more successful technique is to try to recall as much information about the topic as possible, no matter how loosely it is related.

For example, in the situation described in the previous section, I might try to remember the plots and details of other movies I know the performer has been in, as well as what I was doing when I saw the original version of the film and who I was with. I could also try to remember what music was in the film, whether the actress has any brothers or sisters, and even which of my friends said she gave a good performance last time we talked about her.

If I could recall some aspect of the name (such as the number of syllables, or perhaps some of the sounds in the name), I could also try recalling words that sound similar, regardless of whether they are related in meaning to the thing I’m trying to remember.

As you work through these techniques, one of them will likely help you to recall the fact you are hoping to retrieve (in our example, the name of the woman in the movie). If you have other people to bounce ideas off, all the better, because it increases the chance that someone will be able to remember the answer.

Memory is thought to rely heavily on a network of related mental concepts. The technique given here takes advantage of this network to make a difficult-to-recall fact more accessible to consciousness by activating as many related concepts in the network as possible.

One of the key concepts in psychology is priming, in which experiencing or thinking about one concept makes related concepts more readily available to the mind. For example, if the word dinner is shown to people in an experiment, they will react more quickly to words like spoon and vegetable than to words like airplane and paper, because words associated with food and dining are probably more closely and highly interconnected.

By thinking of as many related concepts as possible, you are increasing the activation in the area of memory that your target fact is connected to, thereby making it easier for your mind to lift the fact into consciousness.

The psychologist Endel Tulving proposed a related theory called the encoding specificity principle, which states that successful recall relies on the overlap between the thing you are trying to remember and the situation in which you first encountered it, and the cues or prompts that are available when you are trying to recall it.¹ The technique given here allows you to manipulate the context in your own mind to increase the chances of recall.

Just remembering related facts is only part of the process, however. Research has shown that hearing, reading, or thinking of similar-sounding words can also help overcome the tip-of-the-tongue state.² Models of language and memory suggest that meaning and word structure are stored separately, leading to the experience of remembering facts without being able to recall the word associated with them. In some cases, word structure is only partially remembered, so first letters or syllables are recalled, but nothing else. Priming seems to work as well for sounds as it does for facts and concepts, which is why you can remember the target word more easily by remembering words that sound like it.

Vaughan Bell