When he was broke at age 25 and working at a car dealership, "even though I hated the job, I decided I would throw myself into my sales job 100 percent," Cardone writes in "Be Obsessed or Be Average."
He committed to learning everything he could about sales and the industry. He watched sales training videos while he ate breakfast, listened to self-improvement tapes during his drive to work and was often the first employee to show up and the last to leave.
Cardone's hard work paid off: He went from making $3,000 a month to $20,000 a month in less than a decade.
Today, despite his success, he still works 95 hours a week. In fact, "if you gave me $5 billion, I'd still be grinding tomorrow," he tells CNBC Make It.
On the flip side, if Cardone lost everything and had to start over, he wouldn't be concerned about rebuilding his wealth: "You could take everything away — you could take all the real estate from me, take my name away from me, take the money away from me — as long as I'm free to roam the planet and I have courage and I have creativity and I have commitment, people are going to pay for that. I'll just do it faster next time."
Like this story? Like CNBC Make It on Facebook!
Don't miss: The underused strategy this self-made millionaire uses to get ahead
Video by Andrea Kramar