I was mistaken for a boy while fishing with my dad once. Taking into consideration it was many years ago, I had a hat on, and the guy who said it may or may not have been drinking, it was probably a valid mistake. But still. Scarred for life. It took some serious assistance from La Puberty before I stopped wondering if I looked like a boy everytime I left the house.
I guess I just make a better boy than girl sometimes.