My favorite incidence of historical ignorance was told by my late friend, ex-Chief Master Sergeant Lucien Thomas DFM, (ex-RAF, USAAF, USAF)
Lucien had treated his two daughters to expensive university educations (including -- alas -- Berkeley, London School of Economics, and the Sorbonne.)
One of his daughters and another mid-20s young woman came into the room while Lucien was watching a TV movie about the bombing of Nagasaki.
"Who would do such a horrible thing?" his daughter asked.
Though stunned by her ignorance, Lucien said calmly, "America, of course."
"But why? she squealed. "What did the Japanese ever do to us?"
I would have given $50 to see Lucien's face that day ....