From Guy Kawasaki's Blog:
I read a book (at the suggestion of my buddy Bill Meade) called Why Smart People Do Dumb Things by Dr. Mortimer Feinberg and John J. Tarrant, and it answered this question.
The authors list four reasons why smart, famous, powerful, and rich people who should obviously know better end up crashing and burning:
Hubris. Pride to the point that you no longer feel shame, no longer believe that you are subject to public opinion, and no longer need to fear "the gods." Examples: Gary Hart's involvement with Donna Rice that ended his run for the presidency and the Dennis Kozlowski's (Tyco) $2 million toga party.
Arrogance. From the Latin word arrogare: "to claim for oneself." Arrogant people believe they have claim to anything and everything they want--they are "entitled" to it. King David, for example, felt entitled to the wife (Bathsheba) of one of his soldiers. Modern day King Davids feel entitled to corporate jets and an entourage to tell them that their keynote speech rocked.
Narcissism. Self absorption to the point that you are blind to reality. The world only exists to provide you gratification. Examples: Richard Nixon and Watergate; the Clintons and Whitewater—really just about every politician and CEO who falls from grace.
Unconscious need to fail. If you think failing is hard, try winning. The questions that go through people’s minds when they they are on the doorstep of success are: Do I really deserve to win? Do I want the pressure of constantly having to win in the future? Can I really handle success? Perhaps this explains why professional athletes still take performance enhancement drugs even after watching their colleagues get busted.
The authors go on to discuss maturity (the "capacity to make constructive use of our inmost feelings") and what they call the "Six Basic Principles of Maturity."
Accept yourself. "You’re on the road to maturity if you can begin to appreciate yourself without trying to be what you cannot possibly be." The CEOs who failed at Apple did so because they wanted to be another "Steve Jobs." They couldn't accept themselves and their own, different capabilities and shortcomings.
Accept others. "Your relations with other people are a basic test of your maturity. If you don't get along well with others, it's not because you're not smart enough, or because you're smart and they're dumb. It's because you still need to grow up in some vital centers of your being." For example, there are companies in Silicon Valley that maintain a "tyranny of PhDs" where only the advanced degreed are held in high esteem and marketing, operations, and others are fodder.
Keep your sense of humor. "Your humor reflects your attitudes toward people. The mature person uses humor not as a bludgeoning hammer but rather as a plane to shave off rough edges."
Accept simple pleasures. "The capacity to get excited over things even when they seem ordinary to others—this is a sign of a healthy personality." For example, some tech entrepreneurs have yachts that can barely pass under the Golden Gate Bridge. (I'd just be happy if I could skate backwards.)
Enjoy the present. "Emotional grown-ups don't live on an expectancy basis. They plan for the future, but they know they must also live in the present. The mature person realizes that the best insurance for tomorrow is the effective use of today."
Welcome work. "Appreciation of work is a hallmark of mature people... Immature people are constantly fighting certain aspects of their work. They resent routine reports, or meetings, or correspondence. They allow these annoyances to grate on their nerves continually. Satisfaction in doing a good job is blocked out by the dust speck in the eye of resentment over trivia."
I thought I know what is maturity but this is such a clear listing of qualities, isn't it? I was happy to know about the importance of "simple pleasures" because in the recent few years where my age is inching towards the "better hide it" range, I have started enjoying many things with renewed gusto. It's a very long and growing list but here are some: a strong half-cup of dark and bitter coffee, solving a medium-to-difficult Sudoku puzzle in one sitting, singing a sad song along with Rafi, averting a major escalation by engineering the right sequence of phone and mails...
I like the way two types of humour have been identified: one that you might use as a weapon (the bad kind) and one that helps you smoothen your rough edges (the good kind). I often see a third kind: humour used as a shield (neutral).