I think stories are a tool we use to deal with reality, which otherwise is way to vast and complex. Without stories we are just overwhelmed by it.

Stories are like paint by numbers. Without the numbers there's only dots without a picture.

Another way to look at it is that stories filter information down to a managable level on which things make sense, social bonding happens etc.

But these stories must be constantly evaluated in regards to how far they have strayed from reality. When they lose touch with reality, which is a very common phenomenon when it comes to ideology, for example, they can go on for a long time, but eventually reality will return with a vengeance.