I'm a coin/money collector. I do it partly as a hobby, but also in case I ever get the chance to travel through time and go to the past. I want to make sure I have some old currency on me. I wouldn't want to show up in 1925 with a $20 bill from 2002, for example. The date is printed on it, and the money looks so different. I'd want to make sure I matched the "current" currency. Does anyone else ever think this way? Imagine how rich I'd be with a $100 bill in 1890! That could buy a lot of stuff! So is it normal to think this way?