There was the time, when I was all of 20 years old that someone mistook me for the mother of a person my same age. "So, is that your son?"
How about when I had boy-short pixie hair (poorly cut) in college, and a nasty eye infection that forced me to wear my 6+ year old glasses and I knew I looked ugly, but the little boy in front of me at a baseball game said "Mom, is that a boy or a girl." (His mother was mortified.)
Upon first meeting me, a girl (who was drunk) asked "Do you have a cold?" (it was the middle of the summer). I replied "no." Her response "Oh, you always talk like that?"
Sometimes, in life, you have to take what people say to you with a grain of salt. One off-handed comment might just be an extraneous piece of data, something that should be shrugged off. Now, if I was constantly asked if I had a cold or questioned to be the parent of someone my own age, I would probably have developed a self-esteem complex by now. However, with one or two incidents of embarassing, but odd, encounters like this, all I can do is look back (now) and laugh.