A friend sent me this quote:
Inside your head, you're yakking away to yourself all the time. Getting that voice down on paper is a depressing experience. When you write, you're trying to transpose what you're thinking into something that is less like an annoying drone and more like a piece of music. This writing voice is the voice that people are surprised not to encounter when they "meet the writer." The writer is not so surprised.
Louis Menand, "Bad Comma," The New Yorker, June 28, 2004 (reviewing Lynne Truss, Eats, Shoots & Leaves)