A friend of mine had the exact opposite thing happen a few years ago. He was down in sc going to buy some beer. When he went to the check-out counter the lady said "I'm sorry I can't let you buy that". So he starts going for his driver's license and she responds with "That won't be necessary, I can tell you're under 21". This ends with him calling for the manager and the manager giving the lady behind the counter a dirty look.