Failure is the best teacher, in that things working out the way you want them to almost always has a lower probability than the other way around (i.e. you're very good at basketball, so you should have a good chance of being in the NBA right?) This is why easy success stories are so demoralizing to people; they are hearing about the few who got lucky vs the countless ones who did everything they could to succeed but it just didn't work out.
Because amazing success stories are most likely due to chance, not action. This means that the people who succeeded, especially without first failing a large number of times (like applying to be an astronaut or NBA player; you get one, maybe two chances), haven't learned much about how to accomplish those tasks.
