The thing is, you can go on in life without understanding barely anything. That's one of the wonder of the modern life. You just need to be able to do enough ar

The thing is, you can go on in life without understanding barely anything. That's one of the wonder of the modern life. You just need to be able to do enough arithmetics to buy stuff at the grocery and pays your bills and taxes. For your uncle and friend, understanding something doesn't mean you feel it's going to apply to you. Road accident are not only a matter of physics but also a matter of statistics and risk calculation. Some people are reckless because they can't compute the probability of accident and often underestimate it, feeling that since they think they are good drivers it won't happen to them. Humans in general are bad at assessing risk, it's a very difficult matter.