Seth Meyers was joined by David Letterman to celebrate “Late Night”s 40th anniversary Tuesday.

The show, which was also hosted by Conan O’Brien and Jimmy Fallon before Meyers, launched on Feb. 1, 1982, with Letterman, who was the original host, insisting he wouldn’t have known it had been so long had he not got the invitation.

Letterman spoke to Meyers about having his first NBC morning show cancelled back in 1980.

“It replaced two or three game shows, and it turned out America didn’t want them replaced,” Letterman recalled. “They certainly didn’t want them replaced by me,” admitting his show ran for six to eight weeks.

READ MORE: Alan Kalter, ‘Late Show With David Letterman’ Announcer, Dead At 78

Letterman then said of getting “Late Night” not too long after the cancellation, “It seemed like an eternity because in show business, if you screw something up like blowing up a network’s daytime schedule, it could be a while before they call your number again.”

He explained how he was “consumed by paralytic fear,” telling Meyers, “I was still living with this trepidation that, ‘Well, this can’t possibly go any better than the other one went.’”

Meyers asked, “Did you have a moment then where you started feeling relaxed with the show, that you’d be around for a long time?”

Letterman replied: “I’m trying to think if I had one waiting to come out here.

“No. Show business is awful and ugly,” he said, asking Meyers, “How about you? Now you, Mr. Established, Ready to Go, Here I Am… you’re in good shape.”

READ MORE: David Letterman And Kevin Hart Talk Lizzo, Car Accidents And Realizing What’s Important

Meyers, who has been hosting the show since 2014, insisted people knew his face because of his appearance on “Saturday Night Live”.

“About 18 months,” he replied to Letterman of how long it took him to feel comfortable.

Elsewhere in the interview, Letterman also spoke about the time the “Late Night” animal expert Jack Hanna was bitten by a beaver and had to go to a hospital.

He insisted Hanna didn’t want attention at the time because he was afraid he would embarrass the show, explaining how doctors first thought he’d been shot because of the amount of blood there was.

Police also told Hanna he wasn’t legally allowed to have a beaver in New York City. See more in the clip below.