The aim of school isn’t to make you remember any given fact or theorem. It’s to make you build a mental index of such facts and theorems that resembles the shape of the space itself, such that you can 1. understand the “positioning” or relevance of a new idea in that space; and 2. know where you’d search, and what questions you’d ask, to look up any fact or theorem you hear about, or kinda-sorta remember exists.

The main problem with public schooling is that the system designers (learning-target criteria setters, curriculum designers, textbook publishers, etc.) don’t properly communicate the fact that surveying the field to build a mental map of it, is the goal of primary (and most secondary) education. So you get teachers, parents, and students all worrying about test scores that show that you don’t understand a particular idea, when the curriculum was never designed to communicate particular ideas, but only the structures containing them.