You're only as old as you act

Grocery Store - Phoenix, AZ, USA

(An elderly woman well into her 70s comes through the check-out line with a single bottle of wine. I start to scan the bottle through.)

Customer: "Wait! Aren't you going to check my ID?"

Me: "Er, no, ma'am, I don't think it's really necessary..."

Customer: "Well, that's no good! You should check all ID if you're selling alcohol."

Me: "Well, okay. May I see your ID, please?"

(She hands over an ID card that is obviously fake.)

Me: "...ma'am, this card says you're seventeen."

Customer: "Oh, dear! You've caught me! I'm much too young to be buying this! It's a good thing you were checking IDs. I'd better just go now!

*skips out the door*

Me: "..."