From my favorite webcomic Order of the Stick, in answer to the question, why do we tell stories:
Stories are cool and exciting, funny or sad, silly or deep. They don't need a reason to exist.
Though listening to stories does give us new insights into the human condition, and it is from this vicariously gained understanding that we construct meaning from the randomness of our own lives.
But really it's mostly the "cool" thing I mentioned.I actually think roughly these thoughts whenever I decide to take a break from journal articles or even non-fiction to read some fantasy.