Comment by drakythe
20th century history was covered in depth because much of it can be taught with an American Exceptionalism slant easily. I'm more talking about pre-Roman Empire times.
Though you just reminded me of a co-worker I had while I was in University. She had attended a private Christian High School and apparently world history was optional there because (we worked at a movie rental place) when Valkyrie released I commented on how I didn't care to watch it because I already knew how it would end. She asked what I meant and how I knew, and I had to explain that since Hitler survived the bombing attempt to shoot himself in his bunker at the end of WW2 (or be shot, or fake it, whatever your chosen explanation/conspiracy) in Europe that Tom Cruise's character pretty obviously had to fail. She had _no idea_. I was pretty baffled. My grandad enlisted in the army in the tail end of WW2. 2 generations back. And she knew nothing about it except that it had happened.
None of the history classes in grade/high school I attended advanced after 1900.
However, I knew a lot about WW2 because my dad (and relatives) was heavily involved in it, and also became a historian when he left the AF. He had a mountain of history books, mostly about aviation and WW2. I read some of them, and watched movies like "The Blue Max" and "The Battle of Britain", the "World At War" series, and so on. There are also endless WW2 documentaries on TV.
My neighbor was a paratrooper who lost his leg, my dad's best friend was a P-51 pilot who had his face burned off in combat. WW2 vets were everywhere. They're all dead now, and WW2 is ancient history.