Get Going! Marcel Proust called it exercising the authority of his inner self.
I woke up this morning knowing it's Tuesday and I've committed to riding my bike though I'm really not into it. This early in the morning I'd rather be in bed reading. But once on my bike, I take off down the hill and immediately start feeling really good. And now I'm on my way home with the results of my work; a baguette, a good workout, and several new ideas I want to put to paper.
I realize I do the same with my writing. I go to work at my desk saying I have to do it as if it is a terrible chore. When actually once I get going it is the most fun thing in my life.