After 25 years of studying and counseling self-destructive executives whose behavior was at least as abnormal as Lay's, I can guarantee that what drove him--or, more accurately, caused him to freeze in his tracks as Enron's financial house of cards was collapsing--was far more complex.

Consider what is arguably Lay's greatest offense: In late October 2001, despite receiving several warnings about Enron's accounting practices, Lay promised that Enron would again be wildly profitable.

Many Enron insiders who had heard the same warnings found Lay's statements and inaction bizarre.

Yet one of the best-kept secrets of executive psychology is that, once you achieve success, you become a prisoner to the business model that brought you acclaim.

Before its collapse, Enron was the Microsoft of energy, primarily because of Lay's brilliance. He took a garden-variety company--a union of two pipeline companies--and propelled it to Fortune 100 status. Rather than merely delivering gas to customers, Lay exploited the recent deregulation of pipelines, realigning Enron so that it could trade, at a huge profit, the product that others had to drill wells to extract.

The success of this paradigm shift set the stage for Lay's undoing. Rather than sticking to gas, Enron branched into trading whatever seemed tradable--water, coal, fiber-optic capacity and so on.

Inevitably, Lay stretched this model too far. Before he could realize the damage he had done, success had warped his thinking. Rather than remaining true to the swashbuckling soul that enabled him to seize an opportunity, he grew hyperconservative and became blindly adherent to the business model responsible for his success.

Why else would Lay ignore Enron Vice President Sherron S.Watkins' memo warning that "improper accounting practices" could destroy the corporation? A person who was not overcommitted to his self-styled, abstruse accounting practices would have immediately done an about-face to salvage whatever viable resources he could.

Yet Lay continued to tout the health of Enron and, implicitly, his own business model, just as gamblers who have a "system" that wins don't see that they're throwing good money after bad as losses mount up.

By STEVEN BERGLAS, Steven Berglas, a faculty member of the Harold Price Center for Entrepreneurial Studies, the Anderson School of Management at UCLA, is the author of "Reclaiming the Fire: How Successful People Overcome Burnout" (Random House, 2001)