Sounds like a very wise doctor. Apparently power is another element that fuels the midlife affair in many men. John Edwards attributes his dalliance with Rielle Hunter to hubris, explaining that he strayed because political campaigns feed "a self-focus, an egotism, a narcissism that leads you to believe that you can do whatever you want."
The syndrome is rampant among high-powered alpha-males, Eliot Spitzer being a recent example. Just a few days before Edwards was outed, a bigwig at Credit Suisse was forced to resign due to a fling he'd had with a married woman several years ago. Although the affair ended and he confessed to his wife, his paramour's husband launched a violent internet smear campaign against the financier, spreading such nasty rumors and lies that he eventually brought the honcho down. The writer who covered the story in the NY Times Business section observed that "on Wall Street, the stereotype is that everyone is having an extramarital affair, wining and dining at fancy hotels on the company's tab."
The writer also cites the example of a hotshot who was fired from Goldman Sachs for having an affair with a 24-year-old trading assistant (whom he married and later divorced). He sued the firm for firing him on the grounds that he "believed that numerous high-ranking Goldman Sachs partners and employees had engaged in extramarital sexual relations with other Goldman Sachs employees and that such relationships, widely known at the firm, hadn't hindered the careers of such partners and employees." This was the basis of his case!