Dr. Steven Berglas-executive coach and author-spent most of his professional life on the faculty of Harvard Medical School's department of psychiatry.  And as both coach and psychiatrist, he has become interested in a group of people he calls "serial entrepreneurs."   These are people who make the brave move of starting a business, going through the ups and downs of success and failure.  Then do it again.  And again.  And while most people become "more risk averse" as they get older and more experienced, according to Berglas, these "serial entrepreneurs" only become more spirited and willing to take more leaps. 

And Berglas believes that they are driven by "purpose" more than profit:

Serial entrepreneurs want to make a buck, sure. They might even want to show up a nagging authority figure from their past. But what they really want, above all, is to change the world. (In psychiatry this attribute is known as generativity--a passion to improve the planet for successive generations.) Revolutionizing industries might be one approach; combating an injustice or influencing policy are two more.

Of course serial entrepreneurs take pride in their accomplishments; so, too, do they suffer self-doubt. The difference is that they respond to ups and downs with relative equanimity. Reason: Their work isn't about single victories--building once and settling in for the long, secure fade.

Changing the world is a quest. And that work is never done.

Read Why Serial Entrepreneurs Can't Stop at Forbes, here.