At the grocery store.

Checker: I'll need to see some ID.

Me: What, for that? It's non-alcoholic beer.

Checker: [Flustered] It is? Oh, uh. Well I still need to check your ID.

Me: What, you think I'm a 19 year-old trying to buy non-alcoholic beer?

Checker: [Recovering] No. But I won't sell you non-alcoholic beer if you're over 21. It's the principle of the thing.

You win this round, Mr. Smartypants checker guy.