In 1959, Warren Buffett met Charlie Munger, the beginning of a partnership that has spanned decades and created billions in corporate and personal wealth. Since their fateful meeting, they've built Berkshire Hathaway into one of the world's most successful companies.

"We've had so much fun in our partnership over the years," Buffett told CNBC in a joint interview with Munger, who called the partnership "almost hilarious, it's been so much fun."

Warren Buffett is chairman and CEO of Omaha-based Berkshire Hathaway, where Munger serves as vice chairman, and is six years Buffett's senior.

Few relationships last as long or are as lucrative as their partnership. So what's their secret?

"Obviously, we like each other a lot," Buffett said. "We have minds that work the same way to a great degree. We find the same things quite humorous (and) the things we deplore we agree on."

Munger added they "don't agree totally on everything, and yet we're quite respectful of one another." Buffett told "On The Money" that whenever they do disagree, "Charlie says, "Well, you'll end up agreeing with me because you're smart and I'm right."

Buffett adds he's still looking for a comeback to that line. "I haven't quite figured out the answer to that yet with 56 years of practice."

Both men agree that "a lot" of their outlook on life comes from being born and raised in Omaha, the place from which they both hail, and is Berkshire's headquarters.

"We were raised in a similar environment. We both worshiped our fathers, and we had fathers that deserved to be worshipped," Buffett recalled. Their working relationship began when both held jobs at the Buffett family grocery store.

"I learned how hard it is to work for 10 hours for $2," Munger said with a laugh. Munger also recalled working for Warren's grandfather, Ernest Buffett, as their boss. "He worked us pretty hard … [and] he worked everybody pretty hard, except himself."

Buffett remembered during a blizzard, having to shovel "wet, deep heavy snow all around" the store with another employee.

"We did that for about four hours, we couldn't unclench our fingers," Buffett said. "I looked at my grandfather who said, "What should I pay you boys? A dime is too little and a dollar is too much."

Buffett said with a laugh: "The main thing we learned from the grocery store is we didn't want to work in a grocery store."

Today, their diversified conglomerate, Berkshire Hathaway owns more than 60 companies, including Geico insurance, Dairy Queen and Benjamin Moore paints. Last year, Berkshire earned $24 billion in profits.

As for the secret to their success, the topic of good morals came up. Munger said he didn't think "we deserve much credit" for having good morals, saying early on they "figured out that the world would reward us better if we behaved that way."

"We both have the theory that you should hang around good people," Munger said, "and always behave better every year than you behaved the previous year."

With a laugh, Munger quoted a favorite phrase that his partner uses, "Take the high road, it's uncrowded."

The billionaire investor added: "You do not run into heavy traffic." Munger followed up with the thought: "You have a huge advantage on the high road, there's not too many competitors."

Buffett is 85 years old, and Munger turned 92 earlier this year, and both will be working for the near future. Buffett told CNBC his goal for the next year is one more deal.

"Just one more," he said. "I won't ask for another one. Not until the first one is done."

On the Money airs on CNBC Sundays at 7:30 pm, or check listings for airtimes in local markets.