Brian Chesky’s dad wasn’t thrilled he had decided to go to art school. Chesky promised him he would not move back home to live in their basement, and that when he was done, he’d get a real job with health care benefits.

And he did. But at age 22 he was overcome by a “weird feeling of mortality.” A sense of “this is my life”: Commuting in LA traffic alone to a job in a design company. It was a let down after he’d started to believe the high-minded rhetoric from Rhode Island School of Design that designers could “design the world around them.”

He quit that job, rolled up a foam bed into his crappy Honda Civic and moved in with his old design pal Joe Gebbia in San Francisco. In a bid to pay rent, they opened up their home to attendees of a des...