I like the idea of people who've had some success in one form secretly wanting to be something else; I have some of that myself. I look for it in other people who've established themselves in some particular art form, and then you find out that they really would like to design running shoes, or edit literary magazines or something.
Every weekday morning, I picture my first paragraph while I hike with my dog Milo near Mulholland Drive, looking out over the San Fernando Valley. I edit the paragraph, then memorize it, so that when I get back home and sit down at my computer, the blank screen's tyranny lasts only a second or two. A brief reign!