This happens to me more on the internet than in real life. BUT! When I went to France my friend and I played this game called, "Dude or Chick" Because the girls were so skinny and had such short hair that sometimes it was hard to tell. LOL (No offense France, you're still an awesome place to visit. ) And there is this girl at my school who has decided to dress like a boy, has the facial structure and body of a boy and cut off all of her hair, sometimes I walk past her and wonder if we have a new boy in school.
There is this girl, who cut her hair and she looked like a guy, so when we found that out. I told my friend "You know those manboobs you commented? Those are females" xD and before that I saw her walk into the girls wardrobe I clearly thought that she was a guy and clearly thought that some guys are rude.