I learned a ton about apartheid.
I had no idea how intentional it was, like a master-planned community. I assumed it was a causal result of colonial racism and white superiority. Learning how directed it was really surprised me, and I feel that it is even more insidious.
It also made me realize how one group of people can control another group overtly and also subtly. My mind is now going down a track of how this plays out in America, in our schools -- the guilt of white privilege, etc.