I'm sorry to hear that. I remember when I was in college, I was chatting with my favorite math professors in his office about a special topics course he had offered several semesters prior. It was a special-topics course for particularly high-achieving students, and taught in the style of a seminar. Since he had more freedom with this course, he centered it on a topic of deep interest to him (information theory), and had the hope that he could foster in his students the same passion that he feels towards the material.

And yet, he couldn't believe both the level of apathy from the students and the sheer amount of laziness they demonstrated. Too many students treat their studies as a means to an end, and care only about the material that will be on the examinations. I once overheard some students criticizing a wonderful lab instructor (a grad student) for having the gall to "think he's a professor." He was a nice guy that was genuinely invested in his students beyond what would be expected from a graduate assistant, and yet some students had the gall to twist this around as some kind of flaw.

For what it's worth, I think teaching is among the most noble professions. Some of my absolute favorite instructors were those most often disparaged by other students for expecting a lot of their students. But I benefited immensely by instructors like that, and will always be appreciative of everything they've given me. As much as the vast majority of students don't give your efforts the consideration you deserve, there will always be a small few who will always be thankful.