David Letterman: Why Oprah 'hated me'

Hint: It had nothing to do with the Oscars

David Letterman finally revealed the backstory behind his legendary 16-year feud with Oprah Winfrey.

And he claims it had nothing to do with that awkward "Uma… Oprah!" monologue he gave while hosting the 1995 Oscars.

"This predates the Academy Awards. She hated me long before then," Letterman joked to Jon Stewart on "Late Show" Tuesday night. "We were both having lunch on vacation. I said to [now-wife] Regina, 'Oh, this is hilarious, I'm going to make Oprah buy us lunch'… so the waiter comes over, I said, 'Oh, this woman right there has been kind enough to take care of our check.' As we're leaving, I wave to Oprah… and then we walk. We got  a free lunch and that's where it started!"

The two buried the hatchet in 2005, when Oprah finally visited the "Late Show" after Letterman's many on-air pleas. They held hands and walked across the street to the premiere of the Winfrey-produced "The Color Purple" on Broadway.

In 2003, Winfrey told Time magazine she was "completely uncomfortable" being the target of Letterman's jokes.