Seen the new $20 bill candidate? It's got those little Macintosh rounded corners. The article says:

The Treasury plans to redesign bills every seven to 10 years to keep up with technological advances in counterfeiting.

So when I'm 60 years old, I'm supposed to be able to recognize seven or eight different designs for each currency bill? With my memory slipping already, I'll be surprised if I can do that at 60.