For Bill Gates, the thought of working less than full-time “sounds awful.”

Gates, 68, says he hopes to follow in the footsteps of longtime friend Warren Buffett, who serves as chairman and CEO of Berkshire Hathaway at age 94 and has no imminent plans to retire. “My friend Warren Buffett still comes into the office six days a week,” Gates tells CNBC Make It. “So, I hope my health allows me to be like Warren.”

The Microsoft co-founder still has so much he wants to do, he says. He remains a “technology advisor” for Microsoft, and spends much of his time using his net worth — currently $128 billion, Forbes estimates — to fund potential solutions for the global issues he sees as most pressing, particularly disease, poverty, climate change and access to healthcare and education.

Those issues are the focus of Gates’ latest project: an upcoming five-part Netflix docuseries called “What’s Next? The Future With Bill Gates,” set to premiere on September 18.

“The [Bill & Melinda Gates] Foundation will celebrate its 25th anniversary next year. We haven’t gotten rid of polio, we haven’t got rid of malaria. I’m very, very committed to those things,” says Gates. “We want to cut childhood deaths in half again, from 5 million to 2.5 million.”

That’s a big reason why Gates wants to wait as long as possible significantly lightening his workload, he says.

In his mind, that means “at least 10 years, if my health allows, working at this level,” he says, adding: “Hopefully it’ll be more like 20 or 30.”

The lesson about work that took Gates years to learn

Gates’ current level of work is a far cry from the intensity of his early career, when he was singularly focused on getting Microsoft off the ground and then building it into a tech giant.

“I don’t work as hard [now],” says Gates. “In my 20s, I didn’t believe in weekends and vacations. So, that was kind of out of control, how I pushed myself.” He expected his employees to display a similar attitude, even memorizing workers’ license plate numbers so he could “see when did people come in [and] when were they leaving,” he told BBC in 2016.

It was Buffett who convinced Gates he should go easier on his employees and himself. The billionaire investor assured Gates he didn’t have to “fill every minute in your schedule” to be a serious businessperson, and that it’s more important to control your own time, Gates told journalist Charlie Rose in a joint interview with Buffett in 2017.

“I can buy anything I want, basically, but I can’t buy time,” Buffett added during the same interview.

Gates says he’s changed his ways, telling students at Northern Arizona University’s commencement ceremony last year that he wished someone had told him sooner to “take a break when you need to.” Today, he actually enjoys his free time, he now adds: He plays tennis for fun and takes real vacations, reading up to three hours per day during his time off.

And there’s no shortage of interesting topics Gates wants to learn more about.

“I spent yesterday on Alzheimer’s disease,” he says, adding: “Intellectually, in terms of staying up to date — even just on [artificial intelligence] alone — takes a lot of time. But it’s still incredibly fulfilling.”