Well think on it. Anything that occurs is observed and translated according to what we perceive it to be. So, to me, your take on Hitler's behavior and what transpired may be totally different than mine.
What is real? What is not? We are hard pressed in this day and age to agree upon any definitions of what anything means any longer. It is hard to get our relatives to agree on what happened in a simple family argument. People take sides according to their agendas. Same with the law and a courtroom. We all witness daily how a jury will decide on the most outlandish decisions regarding what transpired and who did what.
It depends on the group consciousness of the moment, I think. I think we all agree that such and such occurred and we have some half-assed documentation supporting that truth.
So, who knows what really happened 200 years ago? Who knows what happened yesterday? Can you prove it beyond a shadow of a doubt?