It's actually quite hard to believe how many people do not wear their seatbelts. You think more people would wear it than don't, but 2 years ago for drivers ed, we had to take 30 minutes at an intersection and count how many people had their seatbelts on and off. The number of people with their seatbelts on was way less than the number with no seatbelt.
Are these people crazy? I would never in my life think of not wearing my seatbelt. That dash, steeringwheel, and windshield are much more solid than my body as a whole. What if you get t-boned from the passenger side and you arent wearing your seatbelt? The car will move over but YOU will not. You'll end up being thrown to the passenger seat and being hit full force by the side of the car, breaking your neck, ribs, arm, leg, etc. With a seatbelt? You might get some very serious whiplash, but that goes away after a few days, unlike breaking bones when you have to deal with it for 2+ months.