When basketball phenom LeBron James was 18 years old, he had to make a huge, potentially life-changing financial decision.
As he recounts in an episode of "Kneading Dough" with Maverick Carter, he flew from the projects of Akron, Ohio, to take a meeting with Paul Fireman, the former chairman and CEO of Reebok. Fireman offered the high school senior $10 million on the spot, under one condition: that James wouldn't talk to Nike or Adidas.
"First of all, it was one of the longest d--- boardroom tables I've ever seen in my life," recalls James. "I had no idea what he was doing at the other end of the table. I just see him writing … He had his head down, he was making sure he didn't get anything wrong on that check, and when he slid it down there, he said: 'Listen … you just promise me you won't go talk to Nike or Adidas and you can take this right now.'"
"I was lost for words at the beginning," James continues. "I flew in from Akron, Ohio, from Spring Hill, from the projects. Our rent is like $17 a month and now I'm looking at a $10 million check."
James, who was "going to homeroom" the very next morning, didn't take the money.
"I started thinking, 'If this guy is willing to give me a $10 million check right now, what's to say that Nike or Adidas is not willing to give me $20 or $30 [million] upfront — or to say that maybe the upfront money is not even the biggest thing,'" he tells Carter. "Maybe let's start thinking about the back-end."
He was inspired by advice from his uncles, who taught him to "never put all your eggs in one basket," James says. "Give people an opportunity to say what they got, to pitch themselves."
James' choice paid off big time: Nike offered the teen a reported $90 million deal. A little over a decade later, James signed a lifetime deal with the brand that may top $1 billion.
But even today, looking back, James says, "I still can't believe I left that $10 million."
Like this story? Like CNBC Make It on Facebook.
Don't miss: LeBron James' business manager Maverick Carter reveals his top-3 negotiating tips
