I've done that in class before. That slow transition to sleep while you pretend your paying attention by agreeing at the right moments.
We have all done this before and is the reason why I think classrooms and auditoriums are a things of the past. You might not like the tutor or the lecture is being explained in a manner that disinterest you or you might hear Yanny when Laurel is being said. So you doze off. I am glad people are opening more up to the idea of educational media like online video classes and detailed descriptions with visible reference material explained in fine detail where you can follow along in your own time and pace. I know very little about "history" now because the teacher I had was about as inspiring as a worn down sheet of sandpaper and I hated him.
