The thing is, with mass media, world unity, and modern communications tech in general, almost everyone who's not ignorant or unable to access a history book knows what happened, and all of the current world powers were involved in the war. Alot of the world was affected by the consequences of WWII. Genocide and war have happened many, many times before in history, but WWII really brought the devastating consequences of it on such a scale into the spotlight. In decades/centuries to come, perhaps the new generations will see it as just a piece of long gone history. But the lessons of world wars should never be forgotten. Of course, history will repeat itself, and WWIII will probably happen sooner or later.