As far as memorizing serial numbers of tendered bills etc. there are a few famous con games played on merchants using just that tactic. One of those requires a co-con who buys for a dollar and pays with a $20 and gets the proper change. The next customer ( the co-con) buys for a dollar, pays with a $10, gets $9 back in change but claims he gave the cashier a $20. Needless to say, he recites the serial # to prove his case. Same game is played with "perfumed money" by those of the female pesuasion. Where the "proof" is that the $20 smells exactly like co-cons purse.
Yes, I know, it was confusing to write too.

Mark

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I'd rather be in Wyoming!