Hop-hop.

However, there are things that simply need to be memorized. Basic formulas, laws, and so on, especially in abstract and exact sciences. And only then can you break everything down and understand it.

In 98% of cases in exact sciences, everything can be derived. 2% are some empirical formulas in physics (initially empirical, let's say), but even they can be explained to some extent. It's better to do it that way.