Oprah Winfrey, David Letterman

Most people remember that David Letterman and Oprah Winfrey once feuded, but not many actually know why. Finally, that not-so-scandalous answer has been revealed.

"I had done a show of his and during the process of the show, people started yelling bad things," Winfrey told CBS News after sitting down with Letterman for an informal chat at Ball State University, Letterman's alma mater. "I thought that he should've taken control of the situation ... it was just such an uncomfortable experience for me."

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But the bad blood is no more. Winfrey appeared on his show after 16 years in 2005 and Letterman later joined her on her talk show. The two have since shot a Super Bowl commercial. "We're friendly friends," Winfrey now says.

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