I get why there's not a lot of talk about the specifics of what Steve did in the war in fanfic, because at least in the movieverse it was 100% HYDRA, 0% Actual Nazis, and also because WWII is super-complicated and writing about that would require a fair bit of research.

But yeah, I think it would be strange and unsettling for him to leave a war still raging and wake up to find history has had sixty-plus years to get it all out in the open and analyze what went down. Having sudden, perfect hindsight about a war you fought in must be strange.