Valve co-founder Gabe Newell has revealed he originally thought he might become a doctor before he had a fateful chance meeting at Microsoft where future CEO Steve Ballmer gave him some pointed advice.

Speaking to YouTuber Zalkar Saliev (via PC Gamer), Newell said when he started programming in high school, it wasn’t necessarily thought to be a real career path. Video games didn’t exist at that time, either, he said. “So when I was a kid I thought I was going to be a doctor, and programming was what I did when I should have been doing something else,” he said. “It wasn’t a career path, you know, there were no classes in it, and my first programmable device was a calculator, a [Texas Instruments] calculator.”

Newell’s brother Dan worked at Microsoft and was an early hire for the company, which was founded in 1975. At the time, Microsoft wasn’t a big player in software development, with Newell saying it was only the third-largest software developer in Washington state. “So there was no notion of having any of the reputation that it would have, say, 10 years later,” he said.

Newell visited his brother at work one day with the expectation that the two of them would just hang out. Newell said Ballmer got upset with him because he was distracting Dan. Newell said Ballmer told him, “‘If you’re going to be hanging out here, you know, why don’t you do something useful?'”

So that’s what Newell did–he took time off at Harvard to “just work at Microsoft.”

Newell never returned to Harvard and instead built a career at Microsoft where he helped build the first versions of Microsoft Windows. He worked at Microsoft for 13 years before leaving in 1996 to start Valve with another Microsoft employee, Mike Harrington. Newell enjoyed tremendous success at Valve, helping steer the company through various game-development projects and the creation of Steam.

Newell is now a billionaire who works from his yacht and goes scuba diving on breaks. Newell also recently revealed the secret to his success.

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