I never really had problems with teachers or professors writing nasty things on papers. I always had issues with the teachers / professors saying nasty things to me or my parents. In 10th grade, during a parent / teacher conference (These were the bane of my existence.), the upper school head asked me what my major would be in college. I told her that I was planning on majoring in marine biology. She laughed, and told me (in front of my mother) that I wasn't smart enough to be a science major and that I should be a theater major instead, because that was the only thing I was good at. After she said that, I was very concerned for her well-being, because I thought my mother was going to slug her. Fortunately (for the head, not for me; I would have loved to see it) she didn't, but explicitly told the head that she had no idea what she was talking about and that she was obviously deranged and unfit to work with students. Oddly enough, a year after I left the school, this head was fired for being an alcoholic and bringing her booze to work.
I also had issues with teachers not believing me when I corrected something they said or wrote on the board. At least once a week, I would correct my english teacher on a piece of grammar that was used incorrectly or a misspelling on the board. And equally as often, I'd get kicked out of class for insubordination. I was never rude or demeaning to the teacher, I just politely pointed out the mistake. Either he / she would announce that I had to be wrong and I'd be forced to get a dictionary and prove that I was right, or I would just be told to "leave my damn room."
Now, granted, I am a bit of a pedant when it comes to grammar or spelling. However, I never saw the need to "show up" the teacher. The mistakes (especially written on the board) would almost glow, and I couldn't focus on anything else until it was fixed. Made me crazy.
...maybe I am a little bit crazy.