The former head of the CIA shares the advice he gave his successor

When Pompeo was first nominated, he sat down with Brennan for about an hour and a half to discuss the new opportunity.

On an episode of Business Insider's podcast, "Success! How I Did It," recorded at an Intersport leadership summit in April, Business Insider US editor-in-chief Alyson Shontell asked Brennan what was said during that 9o-minute talk.

First, Brennan told Shontell, he recommended that Pompeo avoid getting bogged down in partisan politics.

"You really need to put those partisan politics behind," Brennan said. "You really need to make sure that you understand and embrace the responsibilities of an objective, nonpartisan leader of the CIA."

Listen to the whole episode and subscribe to more Success!

Apple Podcasts | RadioPublic | ACast

Brennan continued with some advice that's just as useful for those of us who aren't in the CIA:

"The most important thing for anybody who's going to be taking on that responsibility, is use your first period of time, whether it be six, nine, 12 months, to learn as much as you can about the organization that you're running. Understand how it interacts within itself, how it inter-operates with the rest of the intelligence community and the US government. You really need to have that in-depth understanding and knowledge in order for you to have the wisdom to be able to leverage it for the best of the country's security."

Brennan's suggestion to learn as much as possible about the CIA recalls something Sallie Krawcheck, chair of global professional women's network Ellevate and former CFO of Citigroup, previously shared with Business Insider.

As Business Insider's Linette Lopez reported, when Krawcheck was first picked to lead Smith Barney, Citi's then-new wealth management division, she learned the importance of listening, as opposed to talking. That way, she could get a sense of how the organization worked.

After that, Lopez reported, Krawcheck started every new job with a three-month listening period.

Business Insider's Richard Feloni reported that Arby's CEO Paul Brown also embarked on a "listening tour" when he joined the company in 2013. Brown said he went around to franchise restaurants as well as to restaurants owned by Arby's and asked employees: "What would you do differently if you ran this?" The listening tour helped him bolster Arby's sales.

The point here is that you should use the early days of your job — whether at the CIA, Citigroup, Arby's, or elsewhere — to absorb every detail about the organization, so you can make informed decisions later down the road.

Brennan's final piece of advice to Pompeo?

"There is a distinction between knowledge and wisdom in my mind," he said. "I felt that when I joined the agency, I had a fair amount of knowledge about the Middle East and Arabic and terrorism and other things. But wisdom is using that knowledge and having the ability then to see opportunities, risks, challenges, things that you need to do."