Warren Buffett documentary explores the personal side of the billionaire

If you were to ask Warren Buffett to what he credits his success, he’d tell you he won the ovarian lottery.

“I’m here in my position as a matter of luck,” Buffett says in the new HBO/Kunhardt documentary on his life, Becoming Warren Buffett.

The story of one of the richest men in the world is told through access to never-before-released family photographs, home videos, and interviews with friends and family.

Buffett is considered by many as one of the greatest investors of all time. Through Berkshire Hathaway (BRK-A), he has amassed billions of dollars and controls, or has major stakes in, companies that range from insurer GEICO, reinsurer General Re, railroad Burlington Northern Santa Fe, international energy business Berkshire Hathaway Energy and holdings in other industries including manufacturing, media, real estate and retail. And while many Buffett devotees may be awed by all he's accomplished, the documentary dives into the personal side of a man, too humble to revel in his success.

“He doesn’t take credit for it,” Peter Kunhardt, who directed the film, told USA TODAY. “He says he won the ovarian lottery, he doesn’t try to turn that into: look at me, look at how smart I am and how clever I have been at business."

Buffett calculates the probability of him being born as a male, in the United States, during the 1930s, as contributing largely to his success.

“To think that that makes me superior than anyone else as a human being, I just can’t follow that line of reasoning,” Buffett says in the film. He credits his first wife, Susan, who died in 2004, for his growth and success as a young man. “My first wife used a watering can and sprinkled on me until I became a well-rounded person,” Buffett says.

Despite being separated, Susan and Warren remained close throughout her life. “When you’re that focused on business, there’s side effects," says Kundhart.

Kunhardt tells some of Buffett's story through a session held at a local Omaha high school, not far from the home where he’s lived in since 1958. Where Buffett was reluctant to talk about the most difficult moments in his life, interviews with his children and close friends fill the gap.

“The other part of him is a very human person that has feelings and gets sad when sad things happen. He’s a very different person than when he’s in the Berkshire office,” daughter Susie Buffett told USA TODAY.

Buffett credits Susan Buffett for broadening his politics.  "Civil rights changed my life,” says Buffett. His wife was involved with the movement in Nebraska. A speech by Martin Luther King Jr. influenced him as a young man.  “He believed the way she (Susan) believed in social justice and civil rights,” Susie Buffett recounts.

Becoming Warren Buffett premieres Monday, Jan. 30, on HBO.