it's called propaganda, historical truth is nothing more than synthetic construct created by historians who are paid by governments and other institutions and organizations, to understand history you need to study the archive materials if they exist and they are for most part not accessible for most, they are classified, and even if accessible very few are able to read them or understand them in west average IQ is around 100 (90 - 110) something like 75% of entire society and this is poor, extremely poor.
So most society are unable to understand or evaluate what is true, what remain in society is herd instinct and blind adherence to authority or some conspiratorial thinking(which is better it's mark of some intelligence), to be honest livestock is unable to conspiratorial thinking but is perfectly devoted to authority.
My point is for most humanity popular books and cinema or TV are only source for understanding history, in case of Hitler look no further than your next theater or DVD rental 100's movies on evil Nazis, but what happened in soviet Russia from 1917 to 1939 probably nothing







