Why do we Play Video Games?

So what is it that makes us play video games? Is it just for entertainment purposes, are they played to pass time or so we can escape reality. I would personally say that it is all three of those and every player has their own reasons. But mainly I believe it is because the player wants to be someone their not.
In my case I would have to say it is a bit of each. I play games to pass time, have fun and to be someone that I'm not. Growing up I would have liked to join the military but never did. By me playing games like Call of Duty and Battlefield, it makes me feel like someone I could have been. I always enjoyed military history and shows, so gaming was the perfect opportunity to for me to live out my dream.
I am sure I am not the only one. I am guessing that some other people also live out their dreams of being a professional football player or a Nascar driver by playing these games. As technology advances, the games become more and more realistic which makes it easier for us to fall into this fake world.