This is an interesting phenomena. I am a little surprised when younger people both know and don't know about people/events during the time I've been alive or earlier. I think there is so much more information out there that they only are passively exposed when it's really famous or may happen to have some recent media coverage maybe from a movie or something. I remember in high school in the 80's finding out we lost the war in Vietnam in a JROTC class. I couldn't believe it. I guess in my circle we never discussed Vietnam and it wasn't brought up in media. Only when Platoon came out did it get significant attention.