When Norm Macdonald is the guest on a talk show, especially one hosted by Conan O’Brien, the air in the room changes. Often, he’ll have nothing to promote, and even if he does, he won’t show much interest in promoting it. And the host, if he knows what he’s getting into, might adopt the slightest look of expectant glee, because he knows he won’t be going through the usual motions tonight. Then Macdonald may tell a long, winding joke with a punchline so obvious, you’d never think to use it.

He may, for example, tell a joke about a moth who visits a podiatrist’s office and unloads his depressive thoughts as if he’s talking to a psychiatrist, as he did on The Tonight Show with Conan O’Brien in 2009. The punchline is that the moth visited the podiatrist not because he was seeking help, but because the light was on; but the joke is in the convoluted set-up in which the moth talks about the dehumanizing effects of work, a wife and son he doesn’t love anymore, his dead daughter, and the suicidal thoughts they inspire.

Talk shows are not typically places for experimentation. When guests tell jokes, they tend to frame them as personal stories that are outlandish (in a way that’s likely to get views on YouTube), self-deprecating, or allow for cultural observations. With his moth joke, Macdonald technically follows one of those formats (he acts as if he stole the joke from the driver who took him to the studio), but it’s incidental to the joke itself. He has more interest in zigging where others zag.

He always has. He first gained fame as the host of “Weekend Update” on Saturday Night Live between 1994 and 1997. There, his jokes were blunt and confrontational. Often, his punchlines would simply state what another comedian’s would imply. (“Queen Elizabeth II visited Russia this week, becoming the first English monarch to set foot in the Soviet Union,” one joke began. “The visit, which will last for two weeks, is expected to have absolutely no effect on anything whatsoever.”) And he took pleasure in making his audience uncomfortable. He frequently referred to Michael Jackson as a homosexual pedophile and, for years, Macdonald insisted that he lost the “Weekend Update” job by ruthlessly and repeatedly targeting O.J. Simpson, a friend of former NBC executive Don Ohlmeyer, during his 1995 murder trial. Honestly, it’s a miracle Macdonald lasted more than one season. It’s difficult to imagine an SNL cast member making the live audience gasp or sit in stunned silence as often as Macdonald did.

So it’s easy to understand why he never became the superstar some of his admirers think he should have been. The singular tones and rhythms he uses are best suited to formats where he can speak in monologues, like stand-up performances or talk shows. Comedians rarely save their best for the latter, except for Macdonald, who has turned the talk show appearance into an art form.

In the early ‘90s, Macdonald came looking for trouble. He would sometimes begin an appearance with a sexually explicit non-sequitur; an unstructured, nearly free-associative rapport with the host; or a joke that would end without resolution. His desire to cause mischief would manifest itself as a physical sensation. Often, he would squirm and fidget, as if his subversive instincts were seeking release.

But as he’s grown older, he’s developed another trick: telling jokes so antiquated and inoffensive, they’re more surreal than shocking. During one appearance on Conan in 2016, he described his non-existent wife as a “battle-axe” and told a fake story about looking at himself in the mirror and seeing “a fat, ugly old man.”

“I need you to give me a compliment,” he says to his wife.

“Alright then, your eyesight is damn near perfect,” she replies.

“You dirty dog!” Macdonald counters.

Where Macdonald used to make a game of testing the audience’s patience, he’s moved into testing the conventions that encourage them to laugh. It’s difficult to tell if the jokes are for or on them.

No such confusion exists when a host, O’Brien in particular, brings on a guest who bores Macdonald. When he’s allowed to sit in on the interview — I suspect O’Brien chooses them strategically — Macdonald will interrupt and make jokes at the guest’s expense. This, you realize, is why Macdonald never could have hosted a conventional talk show himself: He can’t resist an easy target.

He didn’t in 1997 on Late Night with Conan O’Brien, when the main guest was Courtney Thorne-Smith from Melrose Place. Macdonald made no secret that he didn’t know who she was, and after she mentioned her upcoming film with Carrot Top — a stand-up comedian whose act is centered around props, and who is unpopular among fellow comedians — he pounced.

When O’Brien asked Thorne-Smith about the film’s title, Macdonald responded before she could.

“I know what it’s going to be called,” he said, while Thorne-Smith sat six inches to his left. “If it’s got Carrot Top in it, you know what a good name for it would be? Box office poison.”

After Thorne-Smith later revealed the film’s actual title, Chairman of the Board, O’Brien sarcastically challenged Macdonald to come up with a joke around it.

“I bet the ‘board’ is spelled ‘b-o-r-e-d,’” he replied.

The joke killed, and sent O’Brien spinning in his chair. Thorne-Smith, who handled Macdonald’s condescension with poise, covered her face with her hand and offered a strained smile.

Beneath Macdonald’s stylistic brilliance and the variety with which he can express it is a hint of internal tension — between the desire to make his audience laugh and the urge to disrupt its expectations. It’s the sort of tension that will bring an incredibly talented person close to stardom, but keep it just out of reach. The effects of that tension became clear on the podcast and web-based talk show, Norm Macdonald Live, that Macdonald began to host in 2013. The show — which features A-list guests and episodes with millions of views on YouTube — could be considered a success by almost any metric. But Macdonald always seems a little embarrassed when talking to famous friends like Adam Sandler and Jerry Seinfeld, like he’s not sure whether they’ve agreed to appear out of charity or genuine interest.

In contrast to the advice you’d expect any talk show host to receive, Macdonald slouches and nearly mumbles his way through many of the episodes, showing little interest in traditional Q&A formats. His conversations sometimes have an insular quality, as if he’s getting lunch with an old friend. Macdonald has long wanted a late-night talk show, but this is not quite it (On March 9, Macdonald announced that he will host a talk show, Norm Macdonald Has a Show, on Netflix, but it almost certainly won’t get the kind of promotion and audience a network talk show receives.). His attitude seems to be: If he can’t have a real talk show, he’ll make it clear how little he cares. (“Everything a talk show has, we have,” he says at the beginning of one episode. “We have guests. We have opening remarks. We have cameras. We have this desk.”)

Oddly, or not, Macdonald seems most comfortable on the show when reading advertisements, which he does with a heavy dose of sarcasm. It’s a chance for rebellion, and the kind of thing he could never get away with on a major network. But Macdonald was never meant to play by anyone else’s rules. He has too much fun ignoring them.