When I meet leftists complaining about the USA I try to remember to ask them if they know anything about Cambodia. So far I have found none that know anything.
The evils of communism are never thought in schools, only Nazi’s
My one daughter heard about the Holocaust early on and started reading up on it at a very young age. She gave a book report in class about it and all the kids said she was making it up. The teacher corrected them, and they formerly learned about it two or three years later in school.
But everybody talks about remembering the Holocaust so that it won’t happen again. I told my kids that it is important to learn about it - but it HAS and WILL happen again. I gave a crash course on the various genocides and evil after WWII. I can’t recall them all now, but Mao, Vietnam, Laos, etc.