A significant number of teens didn't know who Osama Bin Laden was until we killed him. I can't believe it--and yet I do believe it. I didn't know what Iran Contra was when I was in high school, and I was a sophomore when it happened. Teenagers live in their own little world, only tangentially connected to the one the rest of us occupy. Today's high-school freshmen weren't even in Kindergarten when 9/11 happened. Why would they remember?
I think it's just as significant in a way that so many of the people celebrating at Ground Zero and the White House seemed to be college kids. These were people who were nine or ten when the towers came down. I wonder if for them, hearing that Bin Laden had been killed wasn't a bit like hearing that we mowed down Satan, or the Grinch--not the death of a specific person, but striking down the personification of evil in the world.