Some of us are just born record-keepers (4 cents)

I am in my local liquor store, buying our Friday night wine. An obviously homeless man, not particularly well spoken, points to a small bottle of gin behind the counter and say something like: "That 'n". He pulls out some single family bills and a few quarters and pennies and counts out the few dollars needed to acquire his half pint bottle. The clerk puts the money into the register and closes the door. The man stares at the clerk. The clerk look's back with a half quizzical, and half worried look. The man breaks the stare first, and says: "Don't I get a receipt?".