Personally, I write first and foremost, because I enjoy it. Writing is frustrating, but I apparently like frustrating things. Just look at who I married if you want a real world example. (Okay, so most of you don't know him... it's a context joke. Just laugh, trust me on this one.) I would like to say that I could stop writing if I wanted to, but I would be lying. I can give it up and distract myself with other things I enjoy, but I always go back to writing, so yeah, I don't think I could stop if I wanted to. I write because when I write I am happier. If you want to see what I look like when I'm not writing, just look at how I am when I'm not able to work on my books.
Nanowrimo's Key to Creativity that I received for supporting their recent site upgrades by donation.
The thing that surprised me to realize this year was that I have nothing in there about publishing. I have changed my life for my writing, but that does not mean that I have to publish. To be satisfied with my life, I don't need to ever publish. Sharing my writing with my friends is and will always be enough for me, even if I dream of more than that.
I don't know about you, but there is something very freeing about that.