When Norm Macdonald Met Robin Williams - 'The Funniest Man in The World'

"I laughed and laughed and it was like I was in a dream," he explained.

ByABC News
August 12, 2014, 4:02 PM
Norm MacDonald in New York City, April 28, 2012. | Robin Williams in New York City, Sept. 25, 2013.
Norm MacDonald in New York City, April 28, 2012. | Robin Williams in New York City, Sept. 25, 2013.
Theo Wargo/Getty Images | Robin Marchant/Getty Images

— -- According to comedian Norm Macdonald, there was "no one else on the floor" when he met Robin Williams just before his first David Letterman show appearance.

Like so many of those who knew Williams, Macdonald shared a powerful memory of the famously improvisational funnyman.

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Macdonald was just beginning to find success as a professional comedian when "the funniest man in the world" treated him to an experience that he's never since forgotten and never publicly shared.

Until now, via Twitter: