In honor of David Letterman receiving the prestigious Mark Twain Prize for American Humor, Bill Murray and Jimmy Kimmel came together to share what they've learned from the comedian.
The video touches on what it's like being a guest on the show, and what they learned about hosting from Letterman. Apparently, it's easy to tell when Letterman's guests aren't impressing him, with even seasoned comedians like Murray and Kimmel admitting all they want to do is make Letterman laugh.
Watch the video above. Then below, watch 'childhood friends' Fred Armisen and Sam Cooper share their early memories of Letterman.
In other news, watch Will Ferrell and Mark Wahlberg try to make each other LOL with dad jokes.