Ray Bradbury on Writing

...if you are writing without zest, without gusto, without love, without fun, you are only half a writer. It means you are so busy keeping one eye on the commercial market, or one ear peeled for the avant-garde coterie, that you are not being yourself. You don't even know yourself. For the first thing a writer should be is--excited. He should be a thing of fevers and enthusiasms. Without such vigor, he might as well be out picking peaches or digging ditches; God knows it'd be better for his health.

--from Zen in the Art of Writing