Jayson Tatum was just 19 when he learned this NBA money lesson

Jayson Tatum is among the best-paid players in the NBA. At 25 year old, Tatum has already earned $120 million, not counting income from sponsorships, and will make more than $70 million over the next two seasons.

But entering the league as the 19-year-old third overall pick in the 2017 NBA draft, Tatum says he had a lot to learn about money.

"You think you're this super rich young kid and the money will never run out," he said, describing his thought process as a highly-touted prospect. "I learned that that's not at all how it works."

Early on, Tatum absorbed lessons from former players who saw their NBA nest eggs go up in smoke for any number of reasons.

"I'm grateful for all the guys that played in the NBA and went bankrupt and are still around to share their stories, share all the things where they went wrong," he said. "Whether it's bad investments or giving 40 people an allowance every month."

The forward, who recently spoke to CNBC Make It while promoting Gatorade's "Is It In You?" campaign, said one of the dangers he learned about was not how others might get money out of you, but how peer pressure might tempt you to overspend.

He described being in a small locker room with players who are making much more money than you. Seeing their cars in the parking lot or hearing about how they fly on private jets can make you feel like you should be doing that, too.

"You have to understand you're not in the financial place that they are," Tatum said. "You can't live above your means and spend money that you don't have unnecessarily trying to stay up to par with guys that have been in the league 10, 12 years longer than you."

With a nine-figure sum in the bank, Tatum is at the point in his career where he can afford the cars and private flights if he wants to. But over the course of the past few years, he has learned that buying nice things isn't necessarily what makes him happy.

"All the material things, they fill the cup of happiness for a moment," he said. "But there's always a newer car or a newer watch."

Instead, he says the money he has spent taking his family on vacations has been by far the best money he has spent since entering the league.

"Having those memories and being able to have them enjoy experiences that otherwise they never would have been able to have, those by far are the things I enjoy the most," he said. "It's something we can share together."

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