-It expands your horizons. Stories are one of the most effective ways to understand what other people's lives are like. Through reading (or watching) stories, I can envision what it's like to have lived in the American Jazz Age, or go on exchange to France, or be a middle-aged man just trying to do his best, or even what it takes to survive in a world that's fallen apart. This doesn't mean I'm dissatisfied with my own life, but that I'm interested in the world beyond me - which can only be a good thing. Stories help us to to empathise with and care about our fellow humans, making the world a better place. On a more personal level, stories help to shape my ideas of what I do and don't want in my own life. For example: I DO want to travel to Paris and I DON'T want to ever live in a world where the murder of children is a form of entertainment. I DO want to be someone who can save myself, and I DON'T way to be a totally selfish biatch. In this way, stories help you to figure out who you are, what you want and how you can go about getting it. They aren't a distraction from real life - they are about real life.
-It validates your experience. Stories do make you reflect upon your own life and your place in the world - but often, it's not about discovering what's missing or wrong with it, but about what's right. For instance, I read love stories not because my own love life is lacking, but because they are reminders of the importance and power of love, and often reaffirm what's wonderful about my own relationship. I read crime novels because, generally, the bad guys get caught and punished, which reinforces what I feel should happen (even if it doesn't always in real life). I read dystopian novels not because that's the way I want the world to be, but because they are horrific reminder of what humanity should avoid. I read fantasy not because I think the world should be full of unicorns and wizards (although that would be kinda awesome), but because it highlights the true magic in all of us - the power of imagination, of creativity, and of love. All stories, ultimately, are about human experience.
-It connects you with others. This is kinda the same as the point I've already made about how stories validate your experience - but it's also more than that. Because in reaffirming your feelings or beliefs, stories remind you that you're not alone. There are others out there who think or feel exactly as you do. When you can relate to a character, event or even a snatch of dialogue in a book, it's a remarkable revelation. It connects you not only to the fictional characters or universe, but to the very real author who created them. Your heart is touched by somebody you've never even met - somebody who may not even be alive anymore. What could be more magical than that?
-It gives you a way to connect with others. I know, I know, didn't I just cover that? But I wanted to create a separate point for the way stories help you form connections in the real world. Because if we didn't have stories to talk about, what the hell would we do? When you think about it, every conversation contains some kind of story. It's just the way we communicate. In terms of books, TV and movies, frankly, talking about them is often half the fun of consuming them in the first place. It's why we go to movies with the people we love, and watch TV with the Twitterverse. It's why we (or I, at least) blog about books. Because even when you disagree, discussing a particular story with someone can tell you so much about who they are. It helps you to know them, as well as yourself. Plus, there are few things more wonderful than coming across someone who has the same favourite book/TV show/movie as you and feeling a spark of recognition. It's how we find kindred spirits.
-It makes you think. Whether you're ploughing through a literary classic or indulging in the latest YA romance, reading requires brain power. You have to process the language, imagine the action and sometimes even think about the concepts presented to you. Like all the muscles in the body, the brain benefits from exercise - and reading does just that. The same doesn't apply to books and TV quite so much, but the right stories, of course, always give you something to think about.
-It helps you relax. When you're absorbing a story, whether it be via a big screen, small screen or book, chances are you'll be relaxed. Your body is still and your mind is focused. You're in a comfortable position and your breathing slows. Is it any wonder so many people seem to fall asleep within five pages of picking up a book? It's a nice way to unwind.
-It's fun. 'Nuff said.