I get the same thing, unfortunately. Recently I was filling in a form for an A level I am doing at nightclass, when the woman said "you don't have to pay if you are still under eighteen." I was all pleased with myself since I am actually thirty-two. Then my tutor walked in and asked how I was getting on with the paper work. The woman said "I've just about finished with this lad here."
I am five foot ten, eleven stone, with short curly hair, and I used to think quite a feminine face. Okay, so I am relatively big and butch looking, but what about the bloody double d's? Don't they give the game away? Nope, I get it all the time. Tonnes of people think that I am a bloke. And I get women at the gym telling me that if I made more of an effort I could "look pretty" - usually to cover their embarassement for thinking I was a man in the first place.
Does this mean loads of people think Neil is gay? I'll have to ask him if anyone has said anything...