Oh, I know one!
You can't be pretty AND smart.
Where in the world did that come from? lol
I don't like steriotypes, they are annoying and it can really bother people, so you have to be careful about them. BUT I don't think there is anything wrong with joking around or being comical about them, it helps people to lighten up a bit about them as steriotypes are pretty much nonsense.
"Life is an adventure full of beautiful things, and a treasure worth more than gold."