of course i was told discussion of old things was off topic, but the point is that they have told their children and their children's children and so forth until anger at such things has become part of their identity.
Past history is always somewhat distant and somewhat abstract. What happens in your own lifetime is far more vivid, and raises stronger passions.
When a Palestinian child sees his house being demolished by an Israeli bulldozer, why would he not have strong passions and a lifetime hatred of Israel and of nations that he perceives as supporters of Israel?
Note that I am not talking about right or wrong here. I am talking about psychology. If Bush & Co. had properly considered psychology, we wouldn't be mired down in an unwinnable war in Iraq.