Warren Buffett and Charlie Munger have been friends for over 60 years and business partners since 1978. During that time, they've both become billionaires while building Berkshire Hathaway into a $630 billion investment giant.
But, to hear the two wealthy nonagenarians tell it, at least, all of that money wasn't even the biggest prize of their decades-long partnership.
"We made a lot of money but what we really wanted was independence," Buffett, the 90-year-old investing icon, told CNBC's Becky Quick in an interview that aired on Tuesday as part of the special, "Buffett & Munger: A Wealth of Wisdom."
Buffett went on to explain that the "independence" he and Munger sought had to do with having the freedom to choose who they associate with on a day-to-day basis, whether that's in business or their personal lives.
"What's really great is if you can do what you want to do in life and associate with who you want to associate in life, and we've both had that spirit all the way through," Buffett said, calling it "one of the luxuries of life."
Berkshire's success has meant that Buffett and Munger have spent decades calling their own shots in terms of the companies they invest in and the employees or partners they work with, and they've been able to do it all while working closely with each other.
"If we associated with jerks, that was our problem, but we didn't have to. We've had that luxury now for 60 years, or close to it," Buffett added, calling that freedom more important than other trappings of wealth, such as expensive material items: "That beats 25-room houses, or six cars."
"It's better to associate with people who are better than you are," Buffett said, referring specifically to his friendship with Munger.
When CNBC's Quick asked the pair how quickly they can typically determine if someone they meet is a person they want to associate with, the 97-year-old Munger replied: "It's amazing how quickly we do it and how few bad mistakes we make."
"I don't know exactly [what we look for]," Buffett added, though he says he knew right away that he and Munger would hit it off and have a long friendship and partnership after the pair met at a dinner arranged by mutual acquaintances in 1959.
"I knew after I met Charlie, after a few minutes in the restaurant, I knew that this guy's going to be in my life forever. [I knew] we were gonna have fun together, we were gonna make money together, we were gonna get ideas from each other [and] we were both going to behave better than if we didn't know each other," Buffett told CNBC.
When asked what the two friends admire about each other, Munger quickly mentioned the fact that he and Buffett share a similar sense of humor. (Earlier in the interview, Munger noted that he and Buffett immediately hit it off over 60 years ago, thanks to a shared sense of "irreverence," where they didn't take themselves, or others, too seriously.)
"Well, I like the humor, of course, but [him being] dependable is really important," Munger said of Buffett.
Responding to the same question, Buffett struck a more serious note, pointing to Munger's philanthropic efforts, including donating $21 million to the Good Samaritan Hospital and giving hundreds of millions of dollars to construct student dorms at schools like the University of Michigan and the University of California, Santa Barbara.
"He has given to individuals and also to society," said Buffett, who himself has donated more than $41 billion to charity in total, and plans to give away the bulk of his roughly $100 billion fortune as part of "The Giving Pledge."
Buffett added that he's also admired Munger's honesty and fairness as a friend and business partner.
"Charlie's never shaded anything he's told me in terms of presenting it to me in a different way than reality, or he's never done anything I've seen that's self-serving in terms of being a partner in any kind of way," Buffett said. "He makes me better than I would otherwise be and I don't want to disappoint him."
"You had the same thing, in reverse," Munger responded.
Watch CNBC's Warren Buffett and Charlie Munger: A Wealth of Wisdom on YouTube.