You don’t know and you can’t know what it was like. The least you could do is try to listen to the people who were there and perhaps do at least a little bit of introspection and consider what you could’ve done differently, knowing what the consequences for troublemakers were. But that seems to be beyond you?

I think OP is talking about the rise of the Nazis rather than the period where the Nazis were already in control and resistance was much more difficult. Although, in fairness, Hitler was already chancellor ‘90 years ago’.