In high school we had a music teacher who was actually an ok teacher all around and she could be nice with people but she could get incredibly angry with people from one sec to another getting incredibly insulting and stuff.

There's actually a reason why she hated me. There were a few people in our class who actually played instruments and one of them was obviously her favorite. The guy was actually quite alright and one of my friends but he always was treated better than the others (Made him feel like an asshole so many times but hey it's not like it was his fault). So one time we had break before we got her and a few minutes before the start of the next lesson we would screw around in front of the room we had her in. I really regret doing what i did on that day. We rolled up our loose-leaf binders ( i hope that's what it's called ) and basically were hitting each other with it. It was just fun and nobody really put any force in it (Those thin little folders wouldn't have hurt anyways). Well right when i hit the guy who was her favorite student she came around the corner and that started it all up.

Sad thing is we only had a few music teachers on our school so what followed were years of getting insulted, mocked in class and getting bad grades for nothing.

One example would be that each lesson the teacher asked people in pairs about last lesson and what exactly we learned then. When it was my turn you could notice she asked the other person all the easy questions whereas i got all the hard ones. It didn't really matter though because i just had to hesitate a little bit when answering for her to tell me in front of the class that i'm lazy and didn't learn enough so she will just proceed and give me an F. It got better over the years and she eventually at least stopped with giving me bad grades on purpose but it really made me hate that subject for life.