There is a huge billboard of John Oliver in the middle of Times Square, announcing the fifth season of his show Last Week Tonight and causing the comedian to take an alternative route to work. Since he arrived in the US nearly 11 years ago, part of Oliver’s schtick has been the British person not just at sea in another country, but somewhat at sea in his own skin, a comic trope that aligns with the 40-year-old’s fundamental discomfort with the trappings of fame.

“It’s all happened so quickly,” says Oliver, who feels unhappy not only about the poster but, in the British style of ever-decreasing circles of self-consciousness, unhappy about the ingratitude his dislike of the poster might be said to show his employers. “Which I know is bizarre to say, 11 years later, but I don’t feel I’ve come up for breath on any of this yet.” He grins with the boyish incredulity that has become a large part of the appeal of his show. “The fact there is a poster of me in Times Square is absurd.”

It has been a strange thing, particularly for British observers, to watch Oliver transform from Jon Stewart’s vaguely Beatles-like young sidekick into a middle-aged man with the heft – both figuratively and literally – to drive his own hit series. Last Week Tonight, in which he and his team use comedy to animate stories either too complicated or too dull to excite rolling news interest, is a relatively small product in the HBO canon, but clearly a big source of prestige. Watching Oliver land jokes about nefarious town planning, or tease from Edward Snowden confirmation of when the National Security Agency can look at pictures of his penis, not only makes the viewer feel smart, it has the giggly sense of laughing at things we’re not supposed to find funny. At its best – and when it most often goes viral – Last Week Tonight is that rare thing, a highly entertaining show with a measure of social utility (at its worst, it has the over-anxious air of someone trying to tap-dance life into the unmentionably tedious). “We’ve done some really boring things,” Oliver says, with the delight of a man who has bucked every commercial principle in his industry and still come out victorious.

On Last Week Tonight: ‘It’s really, really easy to do these kinds of shows badly.’

A lot of this has to do with Oliver himself. The show has a large team, including eight writers, four researchers, four footage producers and four footage research assistants, which is what it takes to transform a segment about, say, how multilevel marketing targets low-income Spanish Americans from a worthy piece of editorial into a vehicle for comedy that still has the chops to make HBO lawyers nervous. If Jon Stewart, Oliver’s mentor, is urbane and unruffleable, with a comic style that involves a lot of leaning back in his chair, Oliver is the guy who leans feverishly forward, to whom we look for the “holy shit” reaction shot. It’s a tricky tone to nail given that Oliver is, to some extent, still a man with a British accent poking fun at another country.

“I’m sure there’s a lot of go-back-to-where-you-came-from,” he says. “Although that’s so reductive, to think that a single accent dictates whether you can talk about something or not. I think it’s what’s underneath that accent – the intent – which can either be jarring to people or reassuring. It was clear pretty early on that I was coming from a place of emotional investment, and was increasingly saying ‘we’ rather than ‘you’. When I started at The Daily Show, it was often ‘you’ this, ‘you’ that, because it was a simple outsider eye, making fun of something. And that shifted, because I stopped feeling as dislocated. Now I would always say ‘we’ when talking about America.”

Some of that dislocation was alleviated when Oliver met his American wife, Kate, a former US army medic whom he ran into at the 2008 Republican national convention and whose background is so wildly different from his own. And some of it simply fell away through exposure to life in the US.

“That was obliterated pretty quickly,” he says, of kneejerk British condescension towards America. “Because until you’ve been here, you don’t understand just how complicated and, to a certain extent, divided the country is. You see them at the Olympics, chanting the initials of their country as if they all agree on the same thing, and it’s not until you get here that you realise this is barely functioning together. That lazy brush-painting of anti-Americanism was gone pretty quick. And then I started actively to fall in love with the complexities of this country. And that is an odd position to be in, especially now.”

His piece mocking Trump for abandoning his ancestral name was viewed 62m times on Facebook

The Trump presidency, initially assumed to be a gift for late-night comedians, has in reality proven somewhat awkward. If the aim of Last Week Tonight is not to preach to the choir but to convert those on the fence, then this is particularly hard in the case of Trump – a man about whom it is hard to make a subtle joke, and about whom few people are willing to change their opinion. Nonetheless, says Oliver, “we want to keep people. Because otherwise you are in danger of just screaming into an echo chamber.”

The closest the show came to achieving this was in February 2016, when Oliver’s piece “Make Donald Drumpf again”, during which he mocked the then candidate’s abandonment of his ancestral name, went viral in the manner of Tina Fey’s 2008 Sarah Palin sketch and leapt beyond HBO to a huge mainstream audience. The clip, viewed 62m times on Facebook alone, became “way bigger than it should’ve been”, said Oliver, and while this was “joyful”, it also posed a dilemma. “We knew we were going to have more eyes than we necessarily deserved, or would remain on our show the following week,” he says, “and the story that we were working on [next] was on municipal districts, which is dry dry dry.” If ever there was a test of Oliver’s purist instincts, it was the week after Drumpf. He giggles at the memory of the show’s opening monologue. “It was really fun to introduce the topic and say, ‘So this week, we’ll be talking about municipal districts – bye everyone! We haven’t changed! It’s always been this shit! That was an aberration of success that we all just endured!’”

‘Until you’ve been here, you don’t understand just how complicated the country is.’ Photograph: Chris Buck for the Guardian

Had Oliver not received a call from The Daily Show inviting him to fly to the US and audition at the age of 30, one can imagine him now as a bankable and well-loved local performer, taking a sidelong look at the news on Radio 4. After graduating from Cambridge, he had some solid success as a standup, without showing any sign that stardom was imminent. His own expectations weren’t wildly high, either. Oliver grew up in Bedford, the son of two teachers in a household politicised by Thatcher’s spending cuts to education. In his 20s, the idea of earning a living through comedy was miraculous enough.

He also had a firm sense of his own limitations. “As a kid I loved doing plays,” he says. “That’s how I got into it. And as soon as I started doing comedy, that overrode all things, but I’m” – he whispers it – “not a great actor.” He hoots with laughter. “I can act as long as the character is me with a different name. I did that NBC show Community and it was just me. I’m doing the voice of the bird in the [new movie of] The Lion King and it’s going to be me. It’s me. As a bird.”

What he did have in those early years was the respect of bigger names in British comedy. In 2003, Oliver worked with Armando Iannucci on a radio show called The Gash, and at some point he came to the attention of Ricky Gervais, who ultimately recommended him to Jon Stewart. Before 2006, when he auditioned for The Daily Show, he had never set foot in the US. Given the pace and ambition of that show, it is mind-boggling to think that Oliver turned up with, as he puts it, “a fifth-grade understanding of American politics”. In the first six months, he was constantly Googling basic facts about the system of government and trying to catch up on a lifetime of missed references. Even now, after a decade, he still sometimes misses a nuance. I mention a gag he made in the last season of Last Week Tonight that turned on the death of Mary Tyler Moore, a name I find it hard to believe Oliver finds funny in the same way he might, say, Felicity Kendal.

“Yes!” he shouts. “So, Tim Carvell [the series’ showrunner] wrote that joke and it was a perfect joke. And I loved the basic concept behind it, and I know conceptually who Mary Tyler Moore is. But,” he grins, “I don’t feel it. It’s like, an American could make a joke about John Craven, but it wouldn’t come from the same place.” Oliver thinks for a moment. “I believe John Craven was one of the few people who wasn’t a sex offender.”

On Last Week Tonight: ‘I’m sure there’s a lot of go-back-to-where-you-came-from.’

These cultural dissonances occasionally play in Oliver’s favour. On the subject of sex offenders, he says he tried to use the story of Jimmy Savile, wholly unknown in the US, as a way to defamiliarise the debate around the removal of Confederate statues. “It felt like there was a way to get people on board with the concept that a once beloved thing could be recontextualised, to the extent that it was not appropriate to celebrate that thing any more. So, by the time I’d got to Jimmy Savile, saying, ‘Look, we loved him, I wrote to this man, there were statues of him, then we realised those statues had to go… which brings us to our main story: the Confederacy.’ Ah, fuck. But by that point, you basically already agree: which is that things get decontextualised.” (And by the way, he says, “it was amazing explaining Jimmy Savile to people who had no prior knowledge of him – the oddity of that man. To an American eye, there is a sense of: how did you not know? There were certainly some red flags there. You don’t need to have lived with him, like Louis Theroux, to realise there’s something afoot here.”)

Oliver’s show would almost certainly be palatable to a wider audience if he swore less. “That has been said to me,” he says. “I guess it’s worth it to me. I do like swearing, and occasionally, in the stories we’re talking about, a well-placed intensifier feels necessary, to take a little of the air out of a subject.”

It is also a question of not talking down to the viewer. Tonally, the biggest risks for a show like Last Week Tonight are cynicism or condescension; Oliver tries to avoid both by speaking to his audience in an exaggerated version of his regular voice, and by not assuming those who disagree with him are idiots. Take the example of the anti-vaccine movement, he says. “We wanted to deal with the emotional panic that comes with having a kid, and hearing things that are on the surface incredibly frightening – [in order] to keep those people. But then to build the science underneath, so that you can get to the end of it and say, ‘There is no rational debate here.’”

What’s the precise value of clips like Drumpf going viral?

“I guess… zero?” He laughs. “I get that Game Of Thrones has tangible value: that is the tent pole holding this whole canvas up. So I think we’re a really small concern next to these giant international dramas. I literally don’t understand the value that we have.”

When does he feel like he’s been most successful?

“I guess for us it’s often if we feel that we’ve done something really difficult and executed it well. It’s less how it’s received and more, ‘Holy shit, that was hard, and I think that was funny, and a big swing against immensely powerful companies.’”

‘I guess there is a slightly sociopathic side of me.’ Photograph: Chris Buck for the Guardian

He also considers it a success to get people to challenge their own assumptions, including his own. One of the side-effects of his marriage to Kate, with whom he has a two-year-old son, who he is devastated, post-Brexit, won’t have freedom of movement within the EU, has been an overhaul of Oliver’s casual assumptions about the military.

“I think one of the problems in America is that it has this gigantic military that a large amount of the population has no connection to. You can functionally be at war, as they’ve been in Afghanistan, for over a decade, and not really have any emotional sense that that is happening, because the disconnect is so big.” All that changed, for Oliver, after talking to his wife and her friends, and watching her have very different reactions to the news. “There was this one time that Donald Rumsfeld was on The Daily Show and Jon [Stewart] was interviewing him. And Jon said something like, ‘Yeah but the Iraq war had nothing to do with 9/11’, and Rumsfeld kind of laughed and said, ‘Yeah, of course, of course.’ And I remember feeling my wife sort of sink into herself. And she said, ‘That’s not what they told us.’ And that’s hard. It’s hard to watch someone glibly dismiss an idea that had been actively sold to the people who were about to go and, if not die, then witness death.”

On the shallow level, says Oliver, this perspective “stops me disappearing up my own arse, because she has worked in areas where the consequences are significantly more serious than not doing a show as well as you wanted to. I probably don’t have the strength of character to make the decisions that she made.” More profoundly, falling in love with someone with experiences so radically different has proved to Oliver the value of something the show takes very seriously: trying to find a broader empathy with and understanding of others.

All of which sounds very laudable, but of course, the flip side is the comedy of Oliver’s monstrous rudeness. In person he is polite, charming, warm and friendly in a way that is hard to square with his ability to ruthlessly humiliate his interviewees – shouting “Nobody cares!” over Edward Snowden, to stop him descending into impenetrable tech-speak; mocking various politicians to their faces. Even Oliver finds this on-screen rudeness strange. “I can’t send food back [in a restaurant]. I will lie to someone’s face to stop a situation being tense. However, in the context of comedy, when it feels like there’s a purpose, I can be pretty cold. I guess there is a slightly sociopathic side of me that comes down, and as soon as I realised it wasn’t projecting jokes on to an unsuspecting member of the public, I really loved the challenge of it. That meant I was able to distance myself. I could get pretty calm in a room that was absolutely toxic.”

If people knew how long it takes to make our shows, it would be embarrassing

This facility proved useful recently when he interviewed Dustin Hoffman on stage while hosting a panel – which included a very silent Robert De Niro – at the Tribeca film festival, prior to a screening of the 1997 movie Wag The Dog. In an excruciating exchange, Oliver pressed Hoffman on multiple allegations of sexual harassment. When the actor tried to brush him off, he came back for more, until members of the audience booed (others cheered). Oliver said after the event that he considered this encounter a failure; it didn’t lead to anything constructive. I disagree. Watching the footage again, one is struck by how perfectly it exposes Hoffman’s sense of righteous indignation that anyone should be questioning him at all, let alone another “celebrity”.

“I guess I don’t see myself that way, and also because of the context of it… there was no way for me, I felt, to not bring it up. It’s a Wag The Dog screening, a film in which sexual harassment is buried in a gigantic power imbalance. The fact that he would turn up and think I wouldn’t bring it up made me see how little he’d thought about it.”

Still, I think he was shocked that you refused to play the celebrity game.

“I guess. That’s quite insulting to me.” For the first time in the interview, Oliver doesn’t look amused. “I think that’s pretty insulting.”

But I don’t think it’s personal.

“Right, he’s not thinking about me at all.”

Or more that he feels totally inviolable.

“Maybe you’re right. He feels impenetrable, because he has been. Yeah.”

Where was De Niro in all this?

“The thing with Bob is, where is he at any point?” Oliver smiles. “He goes into himself pretty quickly, and that’s whether something dramatic is happening around him or not.” He laughs. “That is a guy who can really bring his blinkers down. I think if you’d asked him at the end of [the discussion] what happened, he could have honestly told you, ‘I don’t know.’”

He didn’t tell you off afterwards? De Niro is the film festival’s co-founder and patron. Oliver looks indignant. “No, no. Of course not. Well, I don’t know why I say of course not… he likes our show and I’ve met him a few times and he’s been very nice. If he was cross, I’d be furious.”

The startling thing about the encounter with Hoffman was that, from Oliver’s point of view, there was nothing funny about it. “I want to be funny all the time, just at a personal level, and there were some moments when I was trying to joke around – but at that point there was such a poisonous atmosphere. [Hoffman] said, ‘I cannot have mistreated women, because I was Tootsie, so I know how women feel.’ That made me laugh. And then you realise, ‘Oh, I’m literally the only person in this room laughing.’ OK, then we’re in really deep, if that’s not funny. In the abstract, that is excruciating to me, and I think it was after the fact. But in the moment, I guess I’ve bombed on stage enough as a comedian. I’m used to audiences not liking me.”

With his wife Kate. Photograph: Getty Images

The question of why shows like Last Week Tonight and The Daily Show have not been replicated in Britain is one that continues to baffle. There have, as Oliver points out, been “a lot of abomination attempts”, although he was a fan of Charlie Brooker’s Newswipe and thinks “with all the talent there is in England” there is no reason why it couldn’t be done. Does he remember The 11 O’Clock Show, the much-mocked satirical news show on Channel 4 in the late 90s, which bore some resemblance to The Daily Show, in format at least?

“Awful!”

Awful.

“There was no voice to that show; it was just an erratic bunch of bullshit. If it voiced anything, it was whoever was executive producing, saying, ‘We need to talk down to people.’ You need a Jon Stewart in that case, and there’s not many of them.”

That is the thing about Last Week Tonight: it is incredibly labour-intensive and, relative to the revenue generated, expensive to make. During the piece about multilevel marketing, producers had the entire segment translated and broadcast in Spanish, being careful not to hire a speaker with a dodgy Californian accent, but a Mexican actor “who could speak Spanish in an accent Hispanic people would listen to”. Every show has elements that get down to this level of forethought.

“It’s a fuck of a lot of work,” says Oliver. “It’s really, really easy to do these kinds of shows badly – your sideways take on the news. If you want to grab low-hanging fruit, that is child’s play. What is hard is to try to do it in a substantive way.” He starts to laugh again. “If people knew exactly how long it took to make our shows, it would be slightly embarrassing.”

Embarrassment, of course, is Oliver’s natural element; he looks utterly delighted.

• Last Week Tonight with John Oliver is on Sky Atlantic on Mondays at 10.10pm, and also on Now TV.

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