"There were two turning points in my life," Buffett said in the HBO documentary "Becoming Warren Buffett." "One when I came out of the womb and one when I met Susie," as he called Susan.
The two met when Susan was going to be rooming with Buffett's youngest sister as a college student at Northwestern University, she says in an old video clip shared in the documentary.
"So I walk into their house, [Warren] was sitting in this chair and he made some sarcastic quip," she recalled. "So I made one back. I thought, 'Who is this jerk?'"
Buffett told Forbes that Susan taught him a lot about investing. He also credits Susan with teaching him to open himself up to the world emotionally.
"I just got very, very, very lucky. I was a lopsided person," Buffett said in the documentary. "And it took a while, but she just stood there with a little watering can and just nourished me along and changed me."
Though you may not have a choice in determining how you were born and raised, Buffett said, "you have something to say about who you marry."
Like this story? Like CNBC Make It on Facebook.
4 questions to ask yourself to figure out what you really want in life
Warren Buffett describes a pivotal moment when he was 20 years old that changed the course of his career