Because Superman is here. And there's a Robin and um fairytale characters and gods and Tony Stark... Yeah, there's a lot. But anyway, we exist just not.. here. OR you can be like you know, Superman and other such and exist but as 'fiction' Which. Hi. I'm part of that club. It seems a lot of people are but not everyone. Or the people who are from here like the Winchesters.
I think that's a pretty common reaction. Even for people used to weird and supernatural and insanity.