As a first point, fiction occupies the role of the role
. That means: It serves as a tool of orientation. Whether that's during our time when we grow up or in later instances. To me, reading or watching stories on the Internet or TV would be a source of knowing "where I stand", so to say, so it has a lot to do with identity and fitting in. I know I compare myself to an illusion, yet I relate to characters that way. Part of "the role" is also displaying role
models. Whether those are positive or negative ones does not matter as much as what the gist is, and what I - we as a collective - can learn from it, especially as fiction draws and crosses conscious boundaries in all possible senses of the word.
A second function of fictional contents as I experience it is insight into human nature and psychology. The way we write, draw, narrate, and how reality surrounds that as well as builds the textual body via the human perception. It also helps me to imagine and spin things around in my own mind by their incentive. It's like the story lives in and through me. That's why I can't watch a movie made out of a book, I already created my own world while reading. Sometimes I like to write prose in private which seems to have its roots in other "fictions" or people I know, so it's interesting to see how everything intertwines, sort of by chance, within my thinking.
Thirdly, and that combines paragraph one and two, fiction is cathartic, i.e. helps us see new points of view to heal. I found an example that's very touching and a reminder of how much we need fictional contexts to broaden our horizon.