I keep a collection of every card I've ever received. Just the other day, I went through the letters I got this year (2012), so I could add them to the archive.
I need to do a better job of checking my cards when I receive them. I found a $50 birthday check and $10 cash from May.
Granny is going to believe me when I say I didn't write her a thank you card, because I just now got her present, right?