49 here, and High-school history class 'finished' not much past WWII/Korean War era. Very little if any touching of the Vietnam war. And at that time it was the same reason. End of school year arrived, and that was as far forward in time as the teacher had achieved. And so that was that.
I'm 48, Italy, and I know about the Vietnam War but not because of school. Same problems you experienced.
I have few memories of it from TV news back then. I remember katyusha missile launchers firing and general happiness when the war was over. But many movies kept remembering everybody about that war. I read books, visited the memorial in Washington when I was there on vacation. I browsed wikipedia in the last years. I studied many wars at school (European history is pretty long) but I know less about most of them than about the Vietnam War. It's pretty easy to get informed even if school didn't care much about that war when we were little. Same about the Korean War.
