Many teachers, in my experience, don’t notice when students are confused or
bored—or maybe they notice but don’t care
Or they notice, and care to some extent, but have other things to worry about. Like a pressure to cover a certain amount of material, or a fear of boring one group of students while they slow down for another, or a (maybe partly justified) belief that the students who are confused and bored just aren’t trying.
Or they notice, and care to some extent, but have other things to worry about. Like a pressure to cover a certain amount of material, or a fear of boring one group of students while they slow down for another, or a (maybe partly justified) belief that the students who are confused and bored just aren’t trying.