During Apple (AAPL) CEO Tim Cook’s five years in the top spot at Apple, he has overseen many product launches and worked to steer the business forward without the company’s iconic co-founder Steve Jobs.

It would be impossible not to learn something new about leadership under those circumstances, and in a recent interview with TheWashington Post, Cook revealed some of the big names he seeks out when he needs help unpacking a problem.

Cook said that when he was looking for a better understanding about giving cash back to shareholders, he got in touch with Warren Buffett, who knows a thing or two about that particular subject.

When he had to testify before the U.S. Senate about the company’s tax practices in 2013, he talked to Goldman Sachs (GS) CEO Lloyd Blankfein, because he thought Blankfein wouldn’t sugarcoat the experience. He also called President Bill Clinton, because why wouldn’t you?

For more on Tim Cook, watch this Fortune video:

Cook said that he has also turned to Laurene Powell Jobs, widow of Steve Jobs, in the past because of her unique perspective about the company’s past and future.

“That doesn’t mean I always do what they say,” he told The Washington Post about his advice seeking. “But I think it’s incumbent on a CEO to not just listen to points of view but to actually solicit them. Because I think, if not, you quickly become insular. And you’re sort of living in the echo chamber.”

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Now, you may not have CEOs or former presidents on speed dial like Cook does, but his insight about using an outside perspective that you trust to get a clearer handle on things is a valuable one. Look to people who have been where you are before, or have an area an expertise that you don’t. It never hurts to see the bigger picture.