Old money
You know how larger monetary denominations -- twenties, fifties, hundreds -- keep getting revised with updated security features? Sure.
Well, let's say you went to the bank and got four $50 bills. One of them is an earlier edition than the other three. Would you spend the old bill first? Of course, you would.
Here's why.
1. If there is some sort of apocalypse and cash's value is diminished, the older bill might no longer be accepted as legal tender.
2. If a cashier is going to make the "Is this counterfeit?" face, you might as well get that over with asap.
3. Superstition.
