Talk to any number of entrepreneurs, and you'll likely discover they all have one thing in common: failure.

That's right, before finding success in business, almost every entrepreneur has had to endure some sort of significant setback, after which they picked up the pieces and started over. So how do entrepreneurs muster the courage to start again, especially considering so many people cite a fear of failure as the No. 1 reason preventing them from becoming an entrepreneur in the first place?

Best-selling author and New Yorker staff writer Malcolm Gladwell explains this phenomenon by pointing to the boldness of World War II-era Londoners during the Blitz. While the Germans thought the city's residents would flee after repeated bombings, what they found was the exact opposite.

The reason for this, Gladwell says--citing psychiatrist J.T. MacCurdy's book The Structure of Morale--is that when people endure a traumatic event, they're often times left feeling empowered, not weakened.

"If the bomb falls across the street and you're fine, you're emboldened. You begin to feel invulnerable," Gladwell says. "The net effect of the bombing was to make Londoners indifferent [and] more courageous."

For entrepreneurs, going through the experience of a failure and not only surviving, but emerging unscathed, results in a uniquely helpful type of overconfidence.

"'Usefully deluded' is the phrase," Gladwell says, adding that many entrepreneurs beat the odds and launch successful businesses precisely because they don't pay attention to the odds in the first place.

"The numbers say you won't succeed, so it's a very useful kind of delusion that entrepreneurs have."

To hear more from the conversation, watch the video below.