No one does. I've religiously watched and consumed it my whole life and I'm still learning. It's a level of complexity that rivals real life. I didn't know about the quotes about Republic credits being the ruler until today!
Discussion
I've barely even started reading the Legends novels, they're regarded as being really really deep too.
I just look up stuff on Wookiepedia for more details just like anything in the Milky Way I want to learn with a regular encyclopedia. Or refer to the historical documents known as Episodes I - VI, Andor, and Rogue One.