You think that's bad? We were in a pub last year (when I was 27) and the barman refused to serve my husband an orange juice for me because I had no ID! As I understand it, you're allowed to buy soft drinks from the bar as of the age of 14, so he was claiming I looked 13! Apparently my wedding ring etc wouldn't suffice to placate him.
A couple of years previously, I got asked my age in Wilkinsons. While trying to buy plastic cutlery!
I often get this problem and I'm very nearly 29. I don't think I look that young either!