Honestly, I can't define precisely why I play video games.
I started to at the age of three with our Calecovision, and then would play the NES. I liked to go outside and was always pretty active, I also loved drawing, and I simply loved television and reading as well. However, there was always something about games that I liked better. I cannot put my finger on it.
Whatever it was, it has stuck with me and then some. I love seeing the industry evolve, and I like seeing how there are still new ideas to be had. Best of all, a lot of the best ideas are beginning to hit video games. For the past decade it has seemed like Hollywood has run out of ideas, yet all of a sudden video games are getting tons of new IP's and then some. Just look at Assassin's Creed. It's insanely more interesting than anything coming out in theaters this holiday. Plus, where else can you get the same sort of entertainment as you get in Portal? Or what sci-fi war movie can compare to the rush you get when you are fighting alongside a buddy in Gears of War?
I guess it was games themselves that made me want to do game design or journalism, but I feel it is the part of me that wants to do design that gives me this desire to play as much as I can that my friends can't keep up with. Yet I love every bit of it.
I guess the best way to answer is that I play because video games are a part of who I am: they are my hobby, and hopefully they'll be my career one way or the other.