David Letterman just gave the most touching tribute to Robin Williams.
The late night host addressed the death of his longtime friend on Monday, and shared some sweet stories about the two comedians when they were first getting started in showbiz.
See what Letterman said about his 38-year friendship with the "Hook" star in the video above.
David and his crew threw together a touching montage of all of Williams' appearances on "The Late Show," and revealed how Robin helped David in Hollywood.
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"I met him at the Comedy Store [in Los Angeles]. He and I were kids, we wanted to make people laugh," Letterman explained. "
"In those days we were working for free drinks. It wasn't until I started the NBC version of this show, it wasn't until then that I sort of got to really know Robin Williams. He would come on to promote movies, or concerts, or whatever he was talking about, and he was always so gracious and we would talk about the old times. It was just a pleasure to know the guy. He was a gentleman and delightful."
The late actor appeared on Letterman's show 50 times throughout his extremely successful career, and every time Williams stopped by the two pals never missed a beat.
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"Really that's what we should take from this, he could make you laugh under any circumstances," Letterman explained, referring to the "Mrs. Doubtfire" star's passing.
"Well, what I will add here is, beyond being a very talented man, and a good friend, and a gentleman, I'm sorry, like everybody else, I had no idea that the man was in pain, that the man was suffering. What a guy, Robin Williams," an emotional David concluded.
See more touching Robin Williams tributes below:
Ben Affleck on Robin Williams: He Made Matt and My Dreams Come True
"Hook" Star Dante Basco Pens Heartfelt Letter in Memory of Robin Williams
Conan O'Brien Reacts to Robin Williams' Death During Show Taping
Allison Williams & Josh Gad Pay Tribute To Robin Williams
Robin Williams Dead at 63 -- Hollywood Reacts