Everybody still believe the landing on Normandy actually happened?
It's been disproven countless of times by credible scholars. Not sure why we, as Americans, continue to perpetuate that myth. Then again, we are largely a populace who lies to their children about a bearded, benevolent gift bringer. But while most adults don't believe in Kris Kringle, they have continually trusted the lie of "D-Day" for 70+ years, and they show no signs of stopping despite the overwhelming evidence to the contrary.
England and Canada (Sword, Gold and Ellen Page) have largely come to grips with the idea that the allied invasion was total bupkis, why can't we!?