A student wrote me this note while submitting his final paper for my upper-division expository class:
This was by far the hardest paper I had to write in my collegiate career. I'm not complaining, I really enjoyed writing it but the difficult part was stopping. I felt that I could explain my story in book form. I felt like I needed to commit more time to it because it needed so much thought and proccesing which made it hard. Your class has been my favorite since I started college and I thank you.
That made my day. "The difficult part was the stopping." Thank you, too.