Twitter and Square CEO Jack Dorsey notched his first billion in 2012.
In Tim Ferriss' latest book, "Tools of Titans," which explores the daily routines and habits of world-class performers, the author asks Dorsey about the most worthwhile investment he's ever made — and it isn't in a tech company, stock or real estate.
"Taking the time to walk to work every day," the self-made billionaire tells Ferriss. "Five miles, one hour and 15 minutes."
During the five-mile trek, Dorsey unplugs. He doesn't email or text. He uses the time to listen to music and audio books, or simply to think and draw inspiration from the streets of San Francisco.
"It's a very clearing time," he tells CNN Money. "I want to put as much unexpected potential in front of me because I think something that you don't plan will always make you think differently."
It's also good exercise, which is a key component of Dorsey's lifestyle and success. His morning routine involves waking up at 5:00 a.m., meditating for half an hour, and doing a seven-minute workout three times through.
"A healthier lifestyle ultimately makes me more creative and allows me to think more cohesively," the CEO tells Y Combinator.