How to study Philosophy without having to memorise

Philosophy is a subject that needs a structural understanding. This means that to develop knowledge over Plato's Republic, for example, one needs to understand not just his political views, but also what his takes are on the anthropological problematic. Every philosopher has a connected way of thinking, and to understand it, one must build a structure over their whole schematic. Almost like building a puzzle.
This is the only way to study Philosophy and enjoy it without having to memorise it. To do this, one must make sure that they can, not only explain that philosophy to another person with their own words, but also that one is able to criticise it, thus being aware of its limitations as well as its strengths.