I kind of feel like I got screwed a little bit in my Linear Algebra class. I did a lot of work and put in a lot of effort into that class and just barely got a C. After the final, I thought for sure I was going to get a D, so the C was a pleasant surprise. Of course, it was still a C, which is still not good.
My physics teacher was one of the worst teachers I have ever had at any level of school and I did poorly as a result.
I was a tad disappointed with my Electrical Engineering class, too. The teacher said I should be able to get a specific grade if I did well on my final and I thought I did really well, yet I don't get the grade. I don't know for sure what happened. Maybe I didn't do as well as I thought I did.
At any rate, I don't think teachers can really screw students just for the heck of it. I mean, it can happen to a certain extent just because of the subject matter. Take an art or English class for example. If the teacher doesn't like your art for some reason or another or doesn't like your writing style or whatever, that can subjectively determine your grade. In a math class or another class like that, you're either right or you're wrong (unless there is partial credit for work, etc.). For the most part, I think my grades have been determined objectively. I guess I'm just disappointed that after all the hard work I put into my classes, I still get kicked in the teeth.