I think they just grow up with some ideas always existing and that shapes their worldview. Eventually, the idea of comics being in newspapers at all is going to seem strange to people. Another horror example, I suppose, would be the slasher film. There are differing views on which one was first, but it's arguable that it was Psycho that really got that subgenre going into what we think of as a slasher film today. That's why some modern viewers watch something like Psycho or the original Halloween and have a hard time imagining these movies ever scaring anyone. But in the context of their times, they were deeply upsetting.