Revision. I've played lots and lots of musical gigs. I love music, I really do, but it has one disadvantage. You can't take it back! You can become a hermit who does nothing but practice (which appeals some days), but then, when you've got an audience, your performance could be totally different than what you've practiced. You can't ask your Carnegie Hall audience if you can redo just that last teensy-weensy little phrase.
But when you write, you can change anything. Cut and paste! Add! Insert! Delete! You can even stare at the computer screen for hours in silence and no one will complain.
Silence. After hearing kids yell at me all day long, I don't want a piccolo ringing in my ears. If I want to induce deafness, I can hold Kyle up to my ear after Liam swipes his toy. Sometimes the click-clack of computer keys is more soothing than the pitter-patter of little feet.
Power. My characters are much more obedient than my children. I can make them do anything they want. Of course, sometimes they don't want to, but they sit there and wait patiently on my hard drive until I tell them what to do next.
Gotta. There's a part of me that can't help it. There have been stretches in my life when I haven't written much, but I've always had a writer's brain. For example, ever since I was a child, when someone said something, I'd always picture their words in quotation marks and add "he said" or "she said" in my mind.
Revenge. Besides becoming rich and famous and sticking it to the mean kids, I can change their names and do anything to them I want. Like adding facial hair in choice places. Or stapling "kick me" signs to their butts. Or throwing them into a heap of maggot-infested roadkill. Ah, what fun.
Therapy. Writing is exposure therapy for me--I can revisit happy or icky things in my past and deal with them all over again. And it's even better because I write fiction, so I can write about it however I want. I can exaggerate or (gasp) lie. I can wallow all I want. The reader doesn't know whether or not someone pulled down my pants at school because it's a novel, and I'm not telling.