How have you used memorization to improve your life?

I learned how to memorize a deck of cards using Derren Brown's method in the early 2000's.

With his method (it's actually 2 methods combined in a logical way) it is a no-brainer to apply the principles to just about anything to do with strings of numbers as well.

So I use it to remember combination locks and phone numbers and that sort of thing. And it works really well for me. Even after years of not touching a lock, I can instantly remember its combination.

On the more useless side of things, I still remember the first deck I memorized back in 2002, even though I don't use that order anymore.