Quit While You're AheadDo it in Vegas to keep your winnings; do it in business to keep from burning out.

Why do entrepreneurs like Mitchell Kapor, founder of Lotus Development Corp., abandon their creations just as they're achieving success? They're smart, says Dr. Steven Berglas, who has spent 20 years studying the paradoxical dissatisfaction of people who appear to be very successful, and who teaches a Psychology of the Entrepreneurial Spirit course at the University of California, Los Angeles.

Kapor mystified many by bailing out of Lotus when it was doing very well and still promising even greater success. But there's a method to Kapor's seeming madness, Berglas explains in his latest book,Reclaiming the Fire(Random House, $25.95). He says many entrepreneurs are stimulated by "eustress," a more desirable cousin of distress, which energizes people rather than merely upsetting them. And smoothly running companies aren't the best places to find eustress, adds Berglas, so the solution for many entrepreneurs is starting new ventures.