We learn by growing older, by suffering, by loving, by bearing with the things we can't change, by taking risks. The things you learn in maturity aren't simple things such as acquiring new information and skills. You learn not to engage in self-destructive behavior. You learn not to burn up energy in anxiety. You discover how to manage your tensions, if you have any, which you do. You learn that self-pity and resentment are among the most toxic of drugs. You find that the world loves talent, but pays off on character.
You come to understand that most people are neither for you nor against you: they are thinking about themselves. You learn that no matter how hard you try to please, some people in this world are not going to love you, a lesson that is at first troubling and then really quite relaxing.
Those are things that are hard to learn early in life. As a rule you have to have picked up some mileage and some dents in your fenders before you understand. As Norman Douglas said, 'There are some things you can't learn from others. You have to pass through the fire.'
From John A. Byrne on the Fast Company Web Blog. I posted earlier - but it bears repeating....