@ ImpracticalDino: Nah, nothing overtly wrong happened. But there are a few different reasons why I don't drive...
1) Probably the biggest reason is because owning a vehicle is so expensive. It's less that I'm concerned with the initial cost, and more that the idea of yearly car insurance is a big turn-off. I don't have enough of an income right now to be able to comfortably afford it. Granted, I could probably simply borrow my mother's jeep if I did drive. However...
2) My mom and brother already share the jeep between them (as my brother doesn't own a vehicle of his own), and between the two of them they use it quite a lot. If I used it as well, then that'd be three of us sharing one vehicle, which could make things overly complicated and/or be inconvenient, or else it might simply limit how much I could use the jeep. This isn't as major of an issue as all my other reasons, but it is something I've thought about.
3) I'll admit I'm uneasy with the mere idea of driving. The intricacies of the road and dealing with other people's road rage is something I'm apprehensive about. It probably wouldn't be so bad if I got used to driving, but all the same, I've never had a strong desire to want to drive, not even when I was younger.
4) Sort or related to the above. There actually was a brief time several years ago when I was learning how to drive and my mother was teaching me, so I have had a bit of practice with it, but I ultimately never really got into it.
5) Overall, I'm not in a position where I
need to be driving anyway. There are friends and family members who are generous enough to give me rides if necessary, but otherwise I'm able to just walk or take the bus anywhere I need to go.
@ Anagnos: "Photosynthesis" is the first word that popped into my head, although I don't think I've used it since high school.

In more recent years, I'd probably go with "drastically"; I just like the way it sounds for some reason.