that sometimes, the students in class forget that you can see them. Nothing like giving a lecture and watching someone check their watch every 5 minutes. Or watching someone put their coat on 15 minutes before class. Or put their notebook down 15 minutes before class ends.
They must think they are invisible.
On the other hand, I doodle during a boring meeting or seminar, and might even bring my laptop. So I am not better, maybe just subtler.
But damn, it hurts my feelings when when even one student isn’t into class. I must remember: You cannot please all the people all the time.
Update: I get OK teaching ratings, too.