Bill Gates and Warren Buffett have been friends for over 25 years. Though the billionaires appear to be very different as Gates has once described himself as a technological nerd while Buffett doesn’t even use email, the two have a warm and genuine friendship.

According to CNBC, the business magnates agree that who you spend time with matters, not only in your personal life, but friendships can also have an impact on your career. In a recent appearance at Columbia University, the duo said that investing in relationships will not only enrich one’s life, as it can also lead to success.

“You will move in the direction of the people that you associate with,” said Buffett. “It’s important to associate with people that are better than yourself.” He added that many would do well to “associate with people who are the kind of person you’d like to be.”

Gates agrees with the 86-year-old and said that some friends do bring out the best in people.

“It’s good to invest in those friendships,” said the Microsoft co-founder.

Indeed, the two have invested in their friendship that Gates clearly remembers the day when he met the “Oracle of Omaha.” In a blog post dedicated to his friendship with Buffett, the 61-year-old said that they met on July 5, 1991.

“I think the date stands out in my mind so clearly because it marked the beginning of a new and unexpected friendship for Melinda and me,” said Gates.

To mark the anniversary of their friendship, the father-of-three shared some of his favorite memories of their time together. Gates posted a 360-degree virtual reality video of him and Buffett titled “Philanthropists in Golf Carts Eating Dilly Bars,” and the pair can be seen riding a golf cart around the 2016 Berkshire Hathaway shareholder’s meeting.

The duo visited the Dairy Queen vendor and got a few frozen treats for themselves. At one point, Buffett started playing the ukulele and he got his friend to sing “I’ve Been Working On The Railroad” with him.

“I’ve learned many things from Warren over the last 25 years, but maybe the most important thing is what friendship is all about,” said Gates. “Everyone should be lucky enough to have a friend who is as thoughtful and kind as Warren.”

For more, check out Jobs & Hire’s report on Warren Buffett's most frugal habits.