"What sort of book are you writing?......Football! Really? You look like you'd write romance novels or children's books."
"Why are you involved with the theatrical society?.....You go on stage? Really? You seem like such a shy, quiet person. I could never pictured you doing that. You ARE a shy person, aren't you? No, really, aren't you?"
Can we just stop the stereotyping, folks? I've really had a gutful. It's one of the downsides of living in a small town.
Yes, we all make presumptions about people based on their appearance. But when you're proved to be wrong about that person, don't tell them what your first impression of them was. Particularly if it was negative (saying the first time you saw me, you thought I was a complete utter legend is allowed).
If someone is my friend now, I don't need to know that they thought I looked like a useless droob the first time they met me. That's not helpful in any way. It's only going to make me paranoid that everyone who meets me will think I'm a useless droob.
Keep your thoughts and revelations to yourself. If you discover someone who is morbidly obese is actually a very competent tennis player, don't tell them, "Ohhh you're really good. I thought you'd be too fat to run."
Acting is acting. You shouldn't be surprised that quiet people can be brilliant on stage. Loud people don't necessarily make the best actors. I know some very loud people, but they quake in their boots at the thought of doing theatre.
Some people need a brain to mouth filter...desperately.