Do people change after something BAD Happened?

Some say “People only change when something bad happens.” I don’t believe that. I have had bad things happened to me and at times I wouldn’t change. I have also seen people go back to doing the same things they were doing after something bad happened to them. It is just that teens now days or even grown ups don’t learn right from their mistakes and they feel they can’t stop doing the things they do because it is a habit. For example, when we were at the assembly last week, we saw a video of teens that were in shock trauma after drinking and driving. These kids looked horrible in the movie and there was this one kid that had been drinking and driving a four wheeler and after he got better, he went back to riding four wheelers and drinking. Now of course he didn’t change not even because of what he went through. Now you see my point, if you don’t want to change something or change yourself you wont do it not even if the worse came to last.