"No one can expect to live very long without experiencing a serious setback in one's life or in one's work.<p>Given the competitive struggle, a growing number of highly successful knowledge workers of both sexes--business managers, university teachers, museum directors, doctors--plateau in their forties. They know they have achieved all they will achieve. If their work is all they have, they are in trouble. Knowledge workers therefore need to develop, preferably while they are still quite young, a noncompetitive life and community of their own, and some serious outside interest. This outside interest will give them the opportunity for personal contribution and achievement beyond the workplace.<p>No one can expect to live very long without experiencing a serious setback in one's life or in one's work. There is the competent engineer who at age forty-two is being passed over for promotion in the company. The engineer now knows that he has not been very successful in his job. But in his outside activity--for example, as treasurer in his local church--he has achieved success and continues to have success. And, one's own family may break up, but in that outside activity, there is still a community."<p>Peter Drucker