At age 20, I devoted my life solely to my job, like Bill Gates did to grow Microsoft.

Bill Gates didn't have billionaire status or a company worth over $3 trillion in mind when he dropped out of college to start Microsoft.

At 20 years old, Gates had a more "dull" definition of success, as he explains to CNBC Make It: "Then, success was simply about: Is my code efficient? Does it function properly? And can this company demonstrate to the world that these microcomputers are powerful?"

In 1976, computer enthusiasts like Gates and Allen were dismissed as "hobbyists" despite their conviction that a technological revolution was imminent. According to Gates, "The magic of software was what captivated me, and I was willing to devote my life, in my 20s, solely to software and one job."

Microsoft's mission statement, which was "a personal computer on every desk and in every home," was considered revolutionary at the time, despite sounding mundane today.

Gates recognized the importance of making money while maintaining a strong focus on creating the best product possible. In his "Open Letter to Hobbyists" in 1976, he emphasized the need for users to pay fair prices for software to ensure that developers, including himself, were adequately compensated to continue developing high-quality software that would drive the industry forward.

Gates' single-minded focus on Microsoft during his 20s, which he describes as "Microsoft-centric," propelled the company to the forefront of the computer age and made him one of the wealthiest people in the world, with an estimated net worth of $128 billion today.

Bill Gates is a polymath who enjoys learning about various subjects, including biology, physics, and climate science. He spends his free time reading about these topics. An upcoming Netflix docuseries called "What's Next? The Future With Bill Gates" will focus on these subjects and is set to premiere on September 18.

How Gates defines success today

Gates' conception of success has undergone a transformation from his youth, he asserts.

Gates now advises everyone to "take a break when you need to," as he regrets his single-minded focus that hindered his work-life balance.

"Gates recently admitted to Make It that he doesn't work as hard now as he used to in his 20s, when he didn't believe in weekends and vacations, leading to a self-pushing lifestyle that was out of control."

The 68-year-old's concept of success is centered on a different query, he states: "Am I contributing positively to the world?" He has vowed to donate "almost all" of his substantial wealth within the next 20 years through organizations such as the Bill & Melinda Gates Foundation and his clean-energy investment group, Breakthrough Energy.

Gates defines success as empowering others through sharing his mistakes, accomplishments, and resources to address issues like malaria and climate change.

He hopes to continue that work for the next few decades, provided his health permits, and adds: "I'm incredibly fortunate to be in a different stage of my life, yet still able to contribute to making a difference."

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