Notably, European countries have much better social safety nets than the US, and fascism is still on the rise. Ergo, you can't even really blame capitalism although it certainly contributed to the problem.
There's "knowing" on a theoretical level, and knowing having experienced it. As the generational knowledge of people that have experienced fascism dies off the younger generations have to learn the hard way. Seems to happen every 100 or so years.
The idea of "European exceptionalism" is no different than the idea of "American exceptionalism". People are fundamentally the same regardless of where they live -- we all have the same base instincts, the same hard-coded tribalistic tendencies, and the same fears. Every population on the planet is susceptible to fascism because it preys on the aforementioned.
i'd argue that there's knowing how things were and there's an undertanding of it. i went through the higher tier of the segregating west german school system under the supervision of very humanist engaged teachers. and yet that system was far from being able to deliver the second.
Which is always a very scary part. Especially over here, people should know better as they have first-hand experience (as a society at least). Seems it's too far past already or something. 😔
I think a large part of the problem is that they don't actually have first-hand experience anymore. Almost everyone who lived through WWII is dead now and humanity seems to be incapable of learning from other people's mistakes.