I've noticed this too. My best guess is that they're written the way the author learned the concepts, without taking the time to find "the simplicity after comp

I've noticed this too. My best guess is that they're written the way the author learned the concepts, without taking the time to find "the simplicity after complexity". (https://en.wikipedia.org/wiki/Shuhari https://en.wikipedia.org/wiki/Shuhari) Makes the writer's job a little easier, but the students' job infinitely harder.