Warren Buffett’s son didn’t realize his father was a billionaire until he was 20

Warren Buffett has long been known for keeping his billionaire status low-key—even from those closest to him. In an interview with Forbes, his son Peter Buffett revealed that he didn’t understand just how wealthy his father was until he turned 20.

Peter, now 67, said he first grasped the scale of the family’s fortune when he saw his father’s name on Forbes’ list of the richest Americans. He recalls the moment with a smile: “Well, it was just then that we learned how much money we had as a family. I’m not kidding.”

He added that it was a surprise for him and his mother and even a source of amusement. “My mom and I were like, ‘That’s funny, right? We know who we are, but now everyone treats us differently.’ It was an interesting shift, though not too dramatic, because we didn’t live in a world where wealth was flaunted. Our friends were just as surprised as I was.”

Warren Buffett, now 95, explained that by that point his children were already grounded and knew who their real friends were. “They were friends with people because they liked them, not because someone was a ‘rich kid’ in the neighborhood,” he said.

Buffett is the father of three children, whom he raised with his first wife, Susan Buffett. Although Warren and Susan separated in the late 1970s, they never officially divorced. Susan died of a stroke in 2004 at age 72, and before her death she introduced Warren to his current wife, Astrid Menks Buffett. The couple married in 2006.

Warren Buffett, who long served as CEO and chairman of Berkshire Hathaway, has previously announced that he plans to leave his fortune—estimated by Forbes at around $143.2 billion—to charity after his death. His children will oversee the fund and distribute the money to nonprofits of their choosing.

His son Howard previously called it an incredible opportunity, saying, “It’s not easy to give away money if you want to do it wisely and effectively. This is an amazing opportunity he’s giving us.”