That's the situation Kurt Long found himself in earlier this month.
Long, founder and CEO of cyber-security company FairWarning, visited Neckar Island, which Branson owns. The two met and played a few friendly tennis matches. After the last match, Branson invited Long to participate in the Virgin Strive Challenge.
Organized by Branson, the ultra-marathon involves biking thousands of miles, scaling live volcanoes, and navigating steep mountains in a fundraising effort to support start-ups focused on helping young people.
"You learn to think of something bigger than yourself," Long told CNBC. "You learn to try big things and manage the risk of it. You experience some failure, you pick yourself up and you keep going."
On the journey, Long realized he wasn't only learning how to cycle more miles than he had ever before. He was learning some key business and career lessons.