One time, before I was in elementary school, some guy in a truck pulled out in front of my mom's Cadillac, and we T-boned him (so to speak). After the crash, I had a big bruise from the seat-belt, and it was annoying as hell. That's why I always wear a chest-protector when I drive, except when I'm not wearing a seat-belt, in which case I don't need it.