Sometimes it's a great idea to be a quitter.
I recently canceled a web hosting package. They offered me 2 free years to stay. So I did. I went online to check something about my cell phone bill, and found out I could get unlimited service for $10 less than I had been paying for 1500 minutes.
So if your contract is up, check for options online, or call to say you'd like to discontinue service. Tell them you found a better deal elsewhere (find one first, so you're ready to answer any questions and so you're not a liar). They may offer you a discount.
Another good time to quit is when you've been working for too long, too hard, without the results you wanted, and you're really tired or disillusioned.
What? You say that doesn't sound like me?
Well, I don't mean to *actually* quit. Just pretend. For a day or two. For an afternoon. If you can't afford that much time, then during your lunch break. You don't have to tell anyone but yourself.
It's a good way to get all those oppressive, busy thoughts out of your head and just look around and enjoy the moment for once.