Want to or Have to...

Here's a question. If you consider yourself a creative person, do you do what you do because you want to or because you have to? Is there an invisible force (muse?) that compels you to drop everything and create? Do friends, bills, and other things that require your attention languish while you are in "the zone"? Have you ever given up eating or sleeping in favor of feeding your creative impulse? I'm interested.