I've never been convinced that teaching history prevents all bad things from happening. Some historical lessons are definitely useful, as how to (or not to) set up systems of leadership, and whatnot, but then I've heard people say these things about curving racism, genocide and the such, which aren't the same concept at all. I think the common theme for what we do want to remember and preserve for future generations, is information of value, specifically. No amount of teaching about past hate will teach love. Only loving, and teaching love will do that.