"I stopped trying to just make as much money as I could a long time ago," Cuban recently told Barbara Corcoran on her "888-Barbara" podcast.
"I got enough money. I value my time a lot more than my next dollar."
Cuban says the shift in mindset began when he became inarguably rich: He and Todd Wagner sold the streaming service they founded, Broadcast.com, to Yahoo for $5.7 billion in stock in 1999.
"When we sold [Broadcast.com], the stock was way up there, and it went up even higher," Cuban told Corcoran.
Though the very first thing Cuban did when the stock went high enough to make him a billionaire was a "little naked billionaire dance," he said at Ozy Fest in 2017, he told Corcoran he realized there are other things in life that are just as important.
"I was like, 'How much money do I need?' I just don't need any more money,'" Cuban said.
That's because money really doesn't buy happiness, according to Cuban.
"Money buys you comfort. Money buys you sanity in some respects. Money takes away a lot of the stress of paying the bills, but it doesn't make you happy," he told Corcoran. "I was happy when I was broke. If you were miserable when you were broke, money is not gonna change that."
"If you were happy, living your life when you were living paycheck to paycheck, and all of a sudden, you make it big, if you're smart, you're gonna love your life even more. And that's what happened to me."
Beside the lack of stress, Cuban says the biggest benefit to having so much wealth is being able to "do things that buy time."
"I can make things happen more quickly by paying a little bit more," he explained. "And that's important, because time is the one asset you can't own, buy or get back."
It's the reason Cuban's first big splurge was a private jet, and he told Corcoran it's why he is now focusing on "disrupting" the healthcare industry in the U.S. (among other things).
"The drug system is such a mess right now," he told Corcoran. "The fundamental problem is, not everybody can get the care they need at a cost they can afford. We have to make people healthier. If people are healthier, they consume less health care until they are older."
After consulting economists, industry experts and politicians, he started a company in the pharma space, "because there are so many inefficiencies [in the current system]. I don't care if I make money at all. I just want to try to look back at some point and say 'OK, I didn't f--- it up.'"
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