I've notice time and time again that, if you ask a teacher a lot of questions, most people will assume you're incompetent.

Interesting -- my experience was that they (the class, but sometimes also the teacher) found me annoying, instead.

During my (brief) venture in college, taking a beginning calculus class, I tended to run way behind the teacher, trying to figure out why he'd done some particular step, and would finally give in and ask about it.

Invariably, he would glance at that step, and go, "Oh, you're right. That's wrong, I should have done..." And trailing off, he would erase nearly half the blackboard, back to the place where I was, and start over from there. About half the class would then glare at me, for having made them have to get rid of all the notes they just took.

Apparently, they were copying everything down whether they understood it or not, whereas I was only writing down what I could actually do. Craziest damn thing I ever saw. (But then, I didn't spend very many years in school, either before or after that point.)