The main reason to restrict access to certain iPad features is to keep your kids from certain content. However, you may also want to restrict your own access to certain features to avoid the temptation to waste time.

For example, suppose you're addicted to the Internet and keep paying way too much for Internet access through your cellular network provider. Simply restrict access to Safari and/or YouTube and remove the temptation from your home screen.

To make this even more effective, have someone else type in a passcode to restrict your access to certain features. Now you won't be tempted to turn off these features since even you won't have the proper four-digit passcode. (Just make sure that you trust the person restricting your access to your own iPad, or else you may never gain access to those features without completing resetting your iPad.)