I have only been truly car-free for a period of about 2 months when I moved from the city (I didn't have a car there but my mom did...and I didn't need one because of public trans so I don't count that as car-free really). Once I moved to the suburbs when I was 17, I needed one. I rode my bike to work (about a mile) for 2 months until I saved enough to be able to pay for my car insurance and then I was able to find a better job.
Unfortunately, living in the American suburbs really precludes one from going totally car-less. Everything is much too spread out and doing a 20 mile round trip on a bike to get groceries is a bit much.
"A bicycle does get you there and more. And there is always the thin edge of danger to keep you alert and comfortably apprehensive. Dogs become dogs again and snap at your raincoat; potholes become personal. And getting there is all the fun."