Tim Cook: Listening to Steve Jobs rather than my friends was 'the best decision of my life'

Apple CEO Tim Cook has an estimated net worth of $625 million, and much of his success is thanks to a risk the late Steve Jobs encouraged him to take 20 years ago: leaving a new, stable and impressive job to join Apple.

Accepting the job was not merely the best decision of his professional life but "maybe the best decision of my life" altogether, Cook told Carlyle Group co-founder David Rubenstein on the June 13 episode of "The David Rubenstein Show."

At 22, fresh out of Auburn University, Cook began a 12-year-long careerat IBM. He started as a production engineer at a time when robotics were beginning to take off, he explained. His next big break was at Compaq, the world's largest supplier of PCs at the time.

Then, Cook says, Apple reached out. Though Apple's size was modest compared to Compaq's, he agreed to speak to Jobs. "Steve had come back to the company," Cook said, "and was essentially replacing the executive team that was there at the time."

Jobs himself piqued Cook's interest: "This was an opportunity to talk to the guy who started a whole industry, the man who started the legacy." And "just minutes" later, Cook was convinced: "I totally shocked myself," he recalled, but he knew, "I wanna do it."

Part of the allure of Jobs, Cook said, was that "there was a sparkle in his eye that I had never seen in a CEO before." Jobs' ability to do "something extraordinarily different than conventional wisdom" — by focusing on the consumer and not just on storage and servers — "was brilliant."

"And the type of questions he asked were also different," Cook said. "Literally before I left, I was thinking, 'I hope he offers me a job, because I really wanna do this.'"

Cook already had a good job at Compaq as a vice president, so his friends didn't understand why he would leave. "They thought I was nuts. Again, conventional wisdom was, 'You're working for the top personal computer maker in the world, why would you ever leave, you've got a great career ahead,'" Cook said. But he felt that he couldn't afford to sit on the opportunity.

"It wasn't a decision you could sort of sit and do the engineering kind of analysis," he said. "That analysis will only say, 'Stay put.'"

Instead, Cook said, he heard a voice in his head quoting the famous exhortation usually credited to 19th century newspaperman Horace Greeley, "Go west, young man, go west."

Only six months into the job at Compaq, Cook left to run worldwide operations at Apple in 1998. He found working with Jobs "liberating," Cook said.

Cook became CEO in 2011 after Jobs died. Over the past seven years, Cook has helped turn Apple into the world's most valuable company. In fact, with a market cap of more than $918 billion, it is close to becoming the world's first trillion-dollar company. In May, Apple's stock shares traded at what was then an all-time high after billionaire investor Warren Buffett praised it as "unbelievable."

If you're curious what it's like to be an Apple investor, here's how much you would have today if you invested $1,000 in Apple 10 years ago.