“It’s time we all got off our asses, left the house, and had fun,” Cuban told Inc. earlier this month, hot off the heels of investing in a live events company. “In an AI world, what you do is far more important than what you prompt.”

Coming from Cuban, the message carries a hint of irony: The former Shark Tank investor has built his career on intensity and outworking everyone in the room. And while he’s long straddled business and entertainment—from owning the Dallas Mavericks to backing high-profile sports ventures—Cuban still positions himself at the forefront of tech trends, including AI.

But when it comes to finding work-life balance, the 67-year-old doesn’t exactly preach moderation.

“If you want to work nine-to-five, you can have work-life balance,” he said on The Playbook, a business and athletics podcast from Sports Illustrated. “If you want to crush the game, whatever game you’re in, there’s somebody working 24 hours a day to kick your ass.”

For Cuban, that grind is literal. Not a fan of meetings, he reads between 700 and 1,000 emails a day on his three mobile devices.

That relentless routine makes his advice about fun sound almost contradictory. But Cuban’s point isn’t that hard work doesn’t matter—it’s that AI doesn’t replace real-world experiences or relationships.

The advice Cuban would give his younger self

Cuban may be worth billions today, but his career started with small-time hustles.

In one of his first sales gigs at age 12, he bought boxes of trash bags for $3 and then turned around to sell them for $6 in his neighborhood—all to save up for a pair of sneakers.

That experience set the groundwork for his work ethic. By the time he became a more serious entrepreneur building out his first tech company, he made ends meet by living with five roommates and never taking a vacation. 

Looking back, if he had to do it all over again, Cuban said he wouldn’t change a thing.

“Don’t stress. Don’t change anything. Have fun,” he told Business Insider in 2015.

“You don’t have to know what you’re gonna be when you grow up,” Cuban added. “You don’t have to have answers. You don’t have to have the perfect major. You don’t have to pick the perfect job. You’re allowed to f— up.”

Business leaders like Richard Branson and Satya Nadella agree: Not everything has to be so serious

Cuban isn’t alone in arguing that life and work don’t have to feel so serious.

When Satya Nadella became Microsoft’s CEO in 2014, one of his first messages to employees was simple: “Have fun, communicate, and accomplish great things.”

It’s something long echoed by billionaire Richard Branson, who believes many businesses take themselves far too seriously—and says it’s even on leaders to role-model fun. 

The 75-year-old British owner of Virgin Group said at the University of Pennsylvania’s Wharton School that “it’s up to the person who’s running the company to be willing to let their hair down, to be willing to be the first to dance on the table at a party, and to be willing to be the first in the swimming pool fully clothed to get the parties going, to make sure everybody has a good time.”