"Learn all about it" is just slang for "I know you're lazy so stop here". I know after hearing about Hitler and how bad he was, I decided to see just why he hated the Joos. I "learned all about it", and there's a very good reason why everything in our society is basically only surface level BS and we never learn jack. If people actually got off their ass and did their own research, people like this dumbass would cease to exist.