You know what I learned about the Nazis from my Grandparents? Not every German was a Nazi. In fact just short above 50% voted for them. And the Nazis didn't start with war and Auschwitz. That was peak Nazi. They started with “Awake, Germany!” and river cruises.
The Holocaust was also possible because far too many people who were essentially decent turned a blind eye and found excuses for the Nazis until it was too late.