Now if I put the colon on the other side of the 3, that says I want everything after 3, so 3 and after. If I say x[3:], that's giving me the third element, 0, 1, 2, 3, and everything after it. So that's going to return 4, 5, and 6 in that example, OK?

x[3:]

The output is as follows:

[4, 5, 6]

You might want to keep this IPython/Jupyter Notebook file around. It's a good reference, because sometimes it can get confusing as to whether the slicing operator includes that element or if it's up to or including it or not. So the best way is to just play around with it here and remind yourself.