Ricky Gervais leans back in his chair, puts his feet up on a padded footstool. “Good, OK,” he says. “Shoot!” He cocks his thumb to his index finger and mimes a pistol firing, though it’s not impossible I imagined that. Had he been wearing a (very cheap) suit and tie, I’m sure he would have absentmindedly fingered the viscose. We are transported back to Slough in the early 2000s; Gervais seems to feel it, too: “As David Brent would say…” he continues, exploding into that familiar mad, jagged laugh.

Conjecture over where Gervais starts and Brent ends has long been a matter for discussion – not least by the 54-year-old comedian himself. Gervais always believed you should write what you know, so when he sat down to create The Office with Stephen Merchant, he set it in the moribund Home Counties where he grew up, in a humdrum working environment not unlike the one where he’d spent the best part of a decade. Brent would rather have been a pop star; the same was true for Gervais, one-time singer of Seona Dancing.

But, of course, Gervais is not remotely like Brent, too. While Brent seemed to sweat insecurity and failure, Gervais has global fame and success. He’s our Woody Allen: a writer-director-performer who works at a furious pace and does exactly what he wants. And, unlike Allen, Gervais continues to stretch himself. This month, he releases what he believes is his most “accomplished, ambitious” movie to date, Special Correspondents, a comic caper made exclusively for Netflix, in which he stars alongside Eric Bana. But then this summer, there’s Life on The Road, in which we meet David Brent 15 years on. Gervais will tour a new stand-up set as well, his first for six years, with the modest aim to decipher “humanity”.

All of which is why we’re in an odd dressing room in north London, Gervais having his photograph taken. Beside us is “the world’s largest mirror” – the kind with light bulbs round the outside – which offers our reflections in unflinching, unsolicited detail. I’m reminded of an airplane toilet. Gervais nods, “and you don’t have TMZ waiting for you when you land to ask you questions about Donald Trump, or someone who’s died. Or someone who’s just had an affair. ‘Really? I watched two films, I don’t know.’” Today he wears a tight T-shirt and jeans, looks fit and healthy, though his back’s a bit dicky (hence the footstool). “That’s not me trying to be cool,” he explains.

Gervais might not show it, but 2015 – wrapping up his sitcom Derek, shooting two films back to back – was the most gruelling year of his career. “Crazy,” he says, but then a little voice, the one that has savagely punctured the brattishness of coddled celebrities four times now as presenter of the Golden Globes, kicks in. “Was that because there were firebombs thrown at you? No, it wasn’t that. There were burning crosses on your lawn? Not that. It was just that the hours weren’t good. I was finishing at four [am] some days.” He cracks up again, the sound like a crisp packet being scrunched. “Within the constraints of what I do for a living it was a very, very hard year.”

To a great degree, Gervais only has himself to blame. He wrote the script for Special Correspondents, “de-Frenching” the original, 2009’s Envoyés Très Spéciaux – a farce about two radio journalists who are sent to report on a war, lose their air tickets and have to fake their reports. He also directed, produced and took a lead role. He chose to go with Netflix, because they offered the greatest creative control, the most money and “I didn’t like noisy cinemas when I wasn’t famous”. He says he picked the typeface for the poster and you don’t doubt him. Gervais did the same for Life on the Road, which will be released in August, and much more besides: the offering includes a double album of original Brent material, so you can play along at home.

This all-consuming way of working began back with The Office. When he and Merchant pitched the show to the BBC, Gervais was “a 39-year-old idiot who worked in an office”. Nevertheless, he demanded that he would play Brent and direct the series. Perhaps because it only cost £140,000 and it was going out on Monday night at 9.30pm on BBC2, they agreed. Gervais doesn’t much like compromising and now he rarely has to.

“It’s funny because I was offered film parts the first week after The Office went out,” he remembers. “I was sent a script and I said: ‘Who’s the lead?’ They said: ‘We want you to be.’ And I said: ‘Well, who’s going to go and see that? You want John Cusack.’ Secretly, I hoped they probably thought: ‘Oh, what integrity.’ They didn’t. They thought: ‘What an idiot! He’s just turned down a film.’ Because most people don’t.”

Gervais has declined some meaty roles – not least parts in JJ Abrams’s Mission: Impossible III and Star Trek films – because, for one thing, he didn’t think he’d be especially good in them, but mainly because they would not add to his “Oeuvre… still embarrassed saying a French word.”

He goes on: “Doing Special Correspondents and Life on the Road in one year, I felt like I was going to big school. Like I could write a series and direct it tomorrow and put it on telly and it’s 23 minutes, it’s good. With a film you’ve got to make it excellent. There’s someone funding it. There are film stars in it. Joking aside, you go to bed at night thinking: ‘This is a big responsibility.’”

The bottom line of such a high-wire approach is that you get a lot of credit when it works (The Office, Extras) and there’s nowhere to hide when it doesn’t (Life’s Too Short). Gervais seems to recognise this pressure, while at the same time making it clear there’s really only one person he needs to satisfy. “I do it all,” he says, “so that I only let myself down, is the honest truth.”

All of Gervais’s work for TV and film has, he thinks, a common theme. “Everything I do is somehow rooted in humanity,” he says. “It’s always about people, it’s always about ego, it’s always about desperation. It’s quite existential. You know, ‘Am I leading a good life?’ That might be because I’m an atheist and I think this is all we’ve got, so you better be nice. And have fun.”

Gervais started to question the existence of God around the age of eight – “the RE teacher got the worst of it” – but then he was precocious in lots of ways. He would lie awake at night in Whitley, in the Reading suburbs, trying to fathom out infinity. He used to climb inside the family’s coal bunker; he’d take a chisel with him because he liked to chip away at the rock to reveal the shiny interior. “I remember having to be careful when I cut it in case I accidentally split the atom,” he recalls. “I’d heard this term ‘splitting an atom’ and thought I might accidentally destroy Reading. Ahh, the weight of the world on my shoulders.”

His father was a labourer, his mother was a housewife; Gervais had two older brothers and a sister, but the age gap was 11 years (his mother told him, aged 13, he was “the mistake”). Still, Gervais was close to his siblings who, he says, treated him “like an experiment”: he could read aged three and was watching Monty Python at 10.

“I didn’t know I was poor growing up, because everyone was in the same boat,” says Gervais. “I couldn’t have bikes, it never really bothered me, but I could have any book. I loved school, I loved learning. Yeah, I never cared for possessions. I still don’t really. I don’t get excited by a car, I don’t wear a watch. I buy the nicest house I can afford in the nicest area I can live in. But never really cared, as you can see” – he runs his hand up and down his clothes. “Get my hair cut in a barbers because, what? It doesn’t interest me, it’s nothing.”

Gervais was smart, but not especially driven. “In the 1970s, there was a big thing at school about people working on oil rigs who were earning £1,000 a day,” he says. “Everyone was saying: ‘Think of that! Seven grand a week!’ And I was thinking: ‘I’d only work one day. Why do you need more than £1,000 a week?’”

His early career seems to back up the idea of someone who was not lazy exactly but almost. Gervais studied philosophy at University College London, stayed on to work at the University of London Union (ULU), first on reception and then as assistant events manager. He met his girlfriend, Jane Fallon, aged 21 and they are still together now.

Did Gervais feel unfulfilled? “No,” he insists. “I thought a job was to pay your way and then the point of evenings was to spend time with your girlfriend and friends having a drink and a laugh. I was still creative: I played in a band, I failed as a pop star, I managed a couple of bands. I wasn’t thinking: ‘Oh my God, this is ticking! I’m 32. I’m a failure.’”

He gives the matter some more thought. “I look back and it would be a bit embarrassing to be a 55-year-old ents manager,” he continues. “Putting on raves. It was touch and go. Likewise, me demanding the BBC: ‘You either have it with me in it and I direct it, or you don’t do it.’ They could have said no and I could be sleeping in a car now. So it turned out well.”

Gervais always suspected that he would bring David Brent back, but he was determined that he didn’t want the setting to be an office again. He also wanted to leave it long enough that it didn’t cloud the rest of his career. Fifteen years on, the time felt right. In the film, Brent is now a sales rep for a cleaning products company called Lavichem, still in Slough. He had a spell managing a young rapper, but that didn’t work out – another parallel with Gervais himself – and now he’s cashing in his pension and taking his holiday leave in one final effort to get an album deal. He’s brought together a group of session musicians and is going on an international tour (thanks to the inclusion of Cardiff on the itinerary).

“The Office was about fame, an ordinary man going through a bit of a midlife crisis,” says Gervais. “Because apart from working in an office for 10 years, the biggest influence on The Office was probably me watching those quaint docusoaps of the 1990s where ordinary people got their 15 minutes of fame. Now the world’s different; it’s harsher. Now people will do anything to be famous. There was no Britain’s Got Talent, no YouTube when The Office was out. There were no news programmes that said: ‘Tweet us with your news.’ The fuck is that? All right: ‘I’ve just seen Godzilla…’”

It’s not giving away too much to reveal that Brent isn’t cut out too well for this new world either. “He’s out of place, out of time,” says Gervais. “In The Office he was 40 and basically with nice people. Now he’s in a room full of alpha males and he’s not the boss anymore and it really is dog eat dog. He’s almost bullied and it’s quite tragic that he’s haemorrhaging money for this dream he’s been sold that he can make it because Susan Boyle did.”

Gervais shakes his head fondly. “A 39-year-old bloke prancing around who’s the boss is a bit undignified; he’s a prat. A 55-year-old rep who’s wasting his hard-earned cash is really sad… but really funny!”

This could sound mean, but Gervais reckons this is where people get him wrong. He has a reputation for being cynical, but he thinks his work is romantic, even sentimental: The Office was a love story; Extras was about friendship; Derek was almost a fairytale, dotted with little parables. The Golden Globes monologues are close to the knuckle, but the targets – the Hollywood glitterati, in a room to receive an award – should, Gervais feels, be big and strong enough to look after themselves.

“Oh, I grew up wanting to do a show like The Waltons,” says Gervais. “I loved honour, loyalty, integrity. Honour, that’s king. Nothing like it. And that’s what we do in drama and comedy: we create our own heroes and villains, so no one really gets hurt. We have the roleplay for the soul, so we go through our emotions and it might make us think: ‘Oh God, I said that to him…’”

Ricky Gervais might not have re-imagined The Waltons yet, but you wouldn’t put it past him. As we finish up, his brain is still whirring. Half an hour earlier, we talked about his family: how one of his older brothers is a painter and decorator and his sister a carer working with the learning disabled. Only now he is fretting that he might have said “handicapped” instead of “disabled”.

“That’s because I’m fucking Brent!” he says – which, of course, is true and also thankfully not.

Special Correspondents is out on 29 April, exclusively on Netflix. Life on the Road is released in August