I was a cashier at a grocery store in a college town. Two people came through my line (separate transactions, but definitely knew each other). Store policy was if they look thirty or over you don't need to ID. So the lady goes first. Cat litter, bottle of wine and I think an onion. I don't ID (she was definitely of age). The man is second. Beer and I think brats. I ID him. He asks why when I didn't ID the lady (he was clean shaven and had a definite case of baby face). I simply told him that no one trying to illegally purchase alcohol would get wine with cat litter. He started laughing, told me she was 26 (he was 29). Kept laughing so hard all the way out of the store that he dropped and shattered his six pack. Luckily the manager was my bagger for that transaction and comped him a new six pack (he thought it was funny too).