A Simple Proof
Many teachers will venture to claim that they need every single minute with the students that they can get because every single minute consists of meaningful teaching—mostly because if they say anything else, it sounds like they are wasting time.
In reality, if you are absent for one eight-hour day of school, you can usually show up the next day and ask “What did we do in class yesterday?”, get the assignments, and finish them in a matter of minutes (maybe hours, on a bad day). Why should you have shown up for those eight hours in the first place? It’s hard to justify.
What was all that lost time spent on?
Well, at school you went to lunch, you had to move from classroom to classroom all day, you had to sit through the teacher calling role, you had to listen to lengthy but redundant explanations of the assignments, you had to sit through a PowerPoint presentation that could have been summed up (as it was when you came back) in a matter of minutes, you had to sit around and wait for other kids that took more time on the assignment than you. You also spent lots of time waiting. Waiting for class to be over, waiting for the lecture to be over, waiting for school to be over, all so that you could go home and do something meaningful with your life.
All this to prove that your time at school isn’t being effectively used. If what was supposed to be eight hours only took me two or less, why should I have shown up at all?