The man leaps out of the shadows and into the light. He bounds across the stage toward his desk, brakes and turns and scampers back stage right, grabs the microphone by its cord and swings it around, letting it thunk on the ground next to his caramel-colored loafers as the CBS Orchestra plays frantically. The audience is on its feet. A fake cityscape frames the man as he hits his mark: a red sticker on the iridescent-blue stage floor of the Ed Sullivan Theater in midtown Manhattan.

The band music ceases, the applause dwindles and David Letterman, jacketless and loosey-goosey, warms up his audience before the the 3,759th taping of "The Late Show." His color and vigor belie the fact that he's spent more time on late-night television than anyone, including his idol, Johnny Carson, who reigned for 30 years. Dave passed that mark in February.

Eleven floors up, the actual New York skyline twinkling outside her dimly lit office, Jude Brennan, Dave's longtime producer, has this to say about her boss getting the Kennedy Center's big rainbow necklace for "exemplary" contribution to the culture: "We're very proud of Dave. But it's probably the worst thing that could happen to him."

There are only a handful of people in the country who put on a suit every weeknight and sit behind a desk on TV to riff and razz on America. There are the third-generation hosts of late-night TV: Fallon and Ferguson, Kimmel and Conan, Stewart and Colbert and Maher. Decades after Joan Rivers guest-hosted "The Tonight Show," women are staking claims on the format (Chelsea Handler on E! and Kathy Griffin on Bravo) and in January ABC will tugboat Jimmy Kimmel, 45, to the 11:35 time slot to compete with the second-generation elders who've hauled the template into the 21st century: Jay Leno, 62, and Letterman, 65, sons of Carson.

One of these sons is now a Kennedy Center Honoree, a title bestowed on Carson in 1993. The Dec. 2 Kennedy Center Honors will be broadcast at 9 p.m. Dec. 26 on CBS.

"I know it's not on merit."

This is Dave in mid-November, 20 minutes after wrapping No. 3,759. "I know I'm not worthy of it."

His legs are crossed in slim dark jeans. He's wearing a sourpuss face italicized by clear-rimmed glasses and a silvery dollop of hair, and a white T-shirt underneath a tuxedo jacket.

"I'm thrilled for my family. They're looking at me like, 'He's not this dumbass now.' It's 'Oh, my God!' So that's good.

"But please, I want people to understand: I know it's not right."

Any true perfectionist would be suspicious of praise, interpreting it as a misunderstanding of what an art form truly requires, and therefore believing a commendation is really an invalidation. But this doubt, this self-defeatism - it's all an essential part of who Dave is and what he does. And it's an essential part of why it's worked for so many years.

There are those Americans, after all, who want to feel coddled and anesthetized as their eyelids droop in front of the television. There's at least one late-night program that satisfies this want; it does slightly better in the ratings.

Then there are Americans who want to teeter on the abyss, cackling with glee at the terrible absurdity of life, as they fight off a fitful sleep. These Americans watch Dave.

"Forget everything but the hour of the show," Dave says. "That's just it. I don't like anything - well, I endure every other aspect of the day. But the part of it I enjoy potentially is the hour of the show."

But don't read into this too much, into why this isolating admission makes him the perfect host for our millennial anxieties and hysterics. He'll resist any consideration that isn't masochistic in nature. He's slippery, this self-described "towering mass of Lutheran Midwestern guilt," and tough to hook.

Letterman struck out for broadcasting when he discovered his comfort with extemporaneous speaking in high school. In the late 1960s, he hosted a madcap radio program at Ball State University and then was the booth announcer and weekend weatherman for a local TV affiliate. He couldn't get hired out of the market, so in 1975 he moved to Los Angeles, intent on eventually succeeding Carson.

Three years later - after ingratiating himself at the Comedy Store, performing on Mary Tyler Moore's floppy variety hour and guesting on nearly every game show under the Californian sun - he did his first comedy set on "The Tonight Show."

Johnny liked him. That was enough to hang a career on. Dave guest-hosted "The Tonight Show" 29 times. In 1980, NBC gave him a short-lived live daytime show that proved too zany and prickly for 10 a.m. Less than two years later the network put him at 12:30 a.m., after Carson, who would eventually favor him as a successor. The Feb. 1, 1982, premiere of "Late Night With David Letterman" began with an introduction cribbed from the narration in the 1931 film "Frankenstein."

"Late Night" was indeed a Frankenstein's monster, in that it was cobbled from different gimmicks of Letterman's scattered young career, stitched together in the spirit of Carson, electrified by its post-midnight positioning, and set loose by a young team of writers and producers who were intent on changing the face of television by doing everything "The Tonight Show" did not, or at least doing it in a way that reeked of wry self-awareness.

Nearly a decade later, after NBC gift-wrapped his dream job for Leno but before he made the move to CBS, Dave appeared on the Aug. 30, 1991, episode of "The Tonight Show." Carson's last question for Dave was this: "We're gonna finish at almost 30 years in May; can you envision yourself 20 years from now doing the 'Late Night' show?"

An incredulous cackle overtook Dave, whose eyes flared in mock shock that he might become his own institution. When he recovered his breath, he said, "Good one, John!"

Twenty-one years and couple months after that, Dave paces during breaks while taping show No. 3,759. After closing the show, he takes the elevator up to his corporate offices on the 12th floor. Once considered a miserable boss, and once given to hurling dressing-room furniture in a depressive self-critical rage after shows, Dave is less kinetic with the postmortem of No. 3,759.

"If we could do a show like this every night I think at the end of the year we'd have a solid C-plus," he murmurs, sitting in his small meeting room. "I don't know that we average a C-plus."