"Those three things-- autonomy, complexity, and a connection between effort and reward-- are, most people agree, the three qualities that work has to have if it is to be satisfying. It is not how much money we make that ultimately makes us happy between nine and five. It's whether our work fulfills us. ... Hard work is a prison sentence only if it does not have meaning.
... They learned the same lesson that Alex Williams would learn nearly a century later-- a lesson crucial to those who wanted to tackle the upper reaches of a profession like law or medicine: if you work hard enough and assert yourself, and use your mind and imagination, you can shape the world to your desires."
Malcom Gladwell, Outliers