At what age do you think it's a compliment to get carded?

Today, Sarah, Chris, and I were food shopping (what else do we do here?).





I had purchased my items and Sarah was following with her one purchase, a bottle of wine. As I turned around to see if she was coming, the store clerk (or whatever he's called en francais) kept his hand on the wine bottle and wasn't letting go. He looked at me and asked if this was my wine purchase, which he was hoping I would answer "oui". I laughed and told Sarah that he doesn't think that you're old enough to buy wine. The legal age here is 16. WELL! She was not impressed! She has just recently attained the legal age aux Etats Unis, which is 21. So, I want to know: what is the age that you stop being insulted and think you are being complimented when you're asked for your ID????