Complicated subjects are simply higher level abstractions built upon lower level, more understandable pieces. If one is able to understand a topic to an appropriate level of abstraction and explain it in layman terms, it follows that with a bit of practice & memorization the idea would become intuitive and more likely to be subject to being utilized effectively.

The goal is to breakdown concepts to an appropriate level of abstraction, identify the pieces that need to be practiced/memorized, and the usefulness of the idea in reality.