Honestly it was a natural progression. I got into marxism which means I got into history. So I binged a lot of history youtube and found I really enjoyed pre-colonial American history, especially the Maya. For a time I scratched that itch with youtube videos, podcast episodes, and documentaries but eventually I came to a point where videos were repeating themselves and I wasn't learning much new. Now, I am a physics major so I read a lot of textbooks and a lot of research papers so I am used to sites like JSTOR and have access to them through my school. So now I spend some of my free time reading about these cultures.

Plenty of alternative sites if you don't have access though ;)