I once said that it's not just the matter of wanting to learn something, there is also the matter of wanting to teach.

The problem here is that the book doesn't seem interested in the second.

I mean, sure, it's nice that you go through all the classes, but... is it necessary? Is this teaching? Not to me.

Either focus on how things work and how to pick things, but going over and over and over over everything is tiring and not helpful. Not to mention there is a lot of things said twice (or even more), which seems focused on making the book bigger, instead of making things clearer.