Since I have cut all automobile-related activities out of my life, I consequently have much more free time. In fact, I have read so many books in the last 8 years, that sometimes I can't think of anything else to read. These books have greatly helped me in my profession and in my leisure activities, including, most recently, stopping freeway expansion in the Bay Area. I use the time I spend riding BART and the bus for reading, socializing, thinking, relaxing, or even sleeping. An honest economic analysis will easily demonstrate that owning a car and driving is much more expensive than using public transit.
Life is too short to waste it behind the wheel of a car.
Riding public transit, and not owning a car, gives one a large amount of free time that can be spent reading and learning. For example, Caltrans is working at a feverish pace to push through the widening of most of the freeways in the Bay Area. And you can bet that land developers aren't wasting any time applying their influence to make it happen. Ultimately, the best reason for not owning a car is that life is simply fuller and more enjoyable without it.