I'm aware of very similar questions previously asked - all with good answers. These usually pertain to following up with a professor after a recommendation. My question is specifically about sending a thank you letter to a professor at the end of a semester.
My current semester is ending in three weeks and it has been my favorite semester by far. My professors taught their material really well and I was engaged non stop from the beginning of the semester. Among my professors, some assigned great homework questions, or lectured really well, or were very accessible during office hours. Overall, I had a great learning experience this semester and I want to express my appreciation because I haven't had a semester like this in the three years I've attended school.
I understand it may seem silly to question what is just a polite and appreciative gesture (I think it's silly myself), but I'm a little intimidated about the impression it will leave on my professors. I want to avoid the stigma of "teachers pet." For this reason, I've considered writing anonymous notes, but that seems creepy.
Kind of a light dilemma but I'd like some input because after thinking about it for a while I think it's an interesting topic. Thank you!