Well I got yelled at by teachers for not expressing my opinion. Ok maybe not yelled, but they did have some hurtful things to say because I was silent all of the time and they kept complaining because I was "zoned out"/daydreaming whatever you wanna call it, as a result of my peculiar stare. In school no matter how little we want to believe it, following a certain, more prominent train of thought is always regarded as better.
My English teacher once told us that when she was in school she answered a question in a test which required you to give your opinion. You know those questions where there is no wrong answer, providing you provide enough facts to back up your response. She replied with an answer which did not follow the conventional train of thought, and she got low marks. She advised us that even though in these questions, which you are supposed to give your opinion and there is no wrong or right answer, the truth is that sharing the same opinion of the teacher and/or establishment is always regarded as better, and you are more likely to score higher marks.