Well, because I can't work one. Two shifts a week makes me 150 dollars a week, which is just enough to live on. I can pay my share of the rent and groceries, and buy the occasional book, bottle of perfume, stack of cardstock or lovely shirt every month.
I (along with Bertrand Russel) tout the benefits of constructive 'idleness'. During the five days I'm home, I'm reading, writing, biking, cooking, zining, doing Other Voices work, and thinking. Why should I spend my days otherwise, if I don't need to?
This past week I've been etsy-ing quite a lot too. If it pays off, it will pay off in cold, hard... paypal deposits.