The man who for years gave TV viewers Stupid Pet Tricks served them up a simple, human one instead: a definitive goodbye.

David Letterman brought 33 years of latenight antics to a close late Wednesday afternoon by taping his last broadcast of CBS’ “The Late Show.” In the final show, slated to be broadcast later this evening, the host acted as if he was emceeing just one more program, based on a screening of the first two segments made for reporters Wednesday night.

“His demeanor seemed to me as it always is. He did not seem emotional at all,” said David Oshinsky, a 45-year-old attorney who attended the taping of Letterman’s finale. “He was clearly cognizant it was the last show, but you would not have read that,” he added.

Despite his cool demeanor, Letterman brought with him outsized surprises, including an introduction featuring President Barack Obama, former president George W. Bush, former president Bill Clinton and former president George H.W. Bush in videotaped segments. “Our long national nightmare is over,” each president said.

And Letterman served up the usual mix of tomfoolery and self-deprecating humor. “I’ll be honest with you,” he said in his last monologue. “It’s beginning to look like I’m not going to get the ‘Tonight Show,'” an obvious reference to the decision made by NBC in the early 1990s to award that program to Jay Leno, rather than Letterman, who then hosted the popular “Late Night” at 12:30 a.m., after  Johnny Carson retired. The maneuver sent Letterman to CBS and began a long process that splintered the audience for the time-slot among two handfuls of hosts across broadcast and cable.

Letterman has hosted “Late Show” since its 1993 inception, and before that pioneered the concept of a looser, less formal talk show with “Late Night,” which he launched in 1982. He has been a pivotal figure in TV’s wee-hours schedule for more than 30 years — longer than Johnny Carson’s tenure on NBC’s “Tonight.”

During that time, Letterman took the genre away from the rigid formula followed by many talk shows and instead developed an early reputation for irreverence. He would have his crew shoot the smashing of a watermelon as it fell off a five-story building or press Rupert Jee, the owner of a deli located right outside the Ed Sullivan Theater, the “Late Show” home base, to put various pranks into practice. Later on in his tenure, Letterman dropped some of his escapades in favor of unfiltered conversation with guests — and viewers at home.

During Wednesday’s taping, which was slated to be the host’s 6,028th latenight broadcast, Letterman had to balance those two attributes with the obvious sentiment in the room. Luminaries Barbara Walters, Steve Martin, Peyton Manning, Steve Martin, Julia Louis Dreyfus, Chris Rock, Tina Fey, Alec Baldwin, Jerry Seinfeld and Bill Murray were among those who took part in a final Top Ten List centered on things the celebrities always wanted to say to the host.

The taping, which ran well over an hour, also featured clips from past shows. Among the scenes were Letterman’s interactions with kids; a 1982 look featuring Larry “Bud” Melman as Santa Claus; and a bit in which Letterman took orders at a Taco Bell drive-thru.

The Foo Fighters played “Everlong,” and the CBS Orchestra, led by Paul Shaffer, enjoyed time in the spotlight during a break, Oshinsky said, playing a tune written by former Mott the Hoople frontman Ian Hunter. Letterman described to the audience how important the Foo Fighters song was to his recovery from heart surgery in 2000.

Letterman spent a good amount of time thanking his “Late Show” writers, producers, crew, and his family. Wife Regina and son Harry were in the audience watching the event. But he finished the program as if it were any other, Oshinsky said, telling the audience, “And now, for the last time on a television program: Thank you and good night.”