By most people's definition, business magnate Richard Branson has "made it." After all, the Virgin Group founder owns or holds interests in hundreds of companies, has accumulated an estimated fortune of $5 billion and even owns a private island.
But you'd never hear Branson say it himself. As the self-made billionaire writes on LinkedIn: "I know I'm fortunate to live an extraordinary life — I've been knighted, met the most extraordinary people and attended the most amazing events — but there's never been a point in my career in which I've felt I've 'made it.'"
He's not the only successful entrepreneur with this mindset. Converse CEO Davide Grasso tells CNBC, "I don't think about making it. I really look at life as a journey — not a straight line — so for me, it's constant learning."
Whether you're promoted to CEO, CMO or project manager, "the moment you're named, it's a beginning," says Grasso. "For me, 'making it' or success is: Am I becoming better? Am I a better CEO today than I was yesterday? Am I a better human being today than I was yesterday?"
Gary Erickson, the founder of Clif Bar, has a similar perspective. "I still don't feel like [I've made it]," he tells CNBC. "Every year that went by, there was so much more competition. … We didn't have time to think about how successful this thing was becoming. We were always in competition, and I think that kept us on our toes and still keeps us on our toes."
Even today, "we never rest on our laurels," says Erickson, who still largely owns Clif Bar with his wife, Kit Crawford.
This mindset could help explain Branson, Grasso and Erickson's wild success. According to Richard St. John, who interviewed hundreds of highly motivated and accomplished individuals for his book "The 8 Traits Successful People Have in Common," the world's highest achievers are never complacent.
They continually push themselves out of their comfort zones and are always improving, "whether it's their career, project, product or service," St. John writes.
Author Thomas C. Corley drew a similar conclusion after his five-year study of rich people: "In the case of self-made millionaires, they experiment with new things, new ideas and new people," he writes on Business Insider. While the average person tends to find peace of mind in familiarity, rich people leave their comfort zones in order to keep improving, no matter how much success they've seen or wealth they've built.
"The way I see it, life is all about striving and growing," Branson says. "I never want to have made it; I want to continue making it!"