Around halfway through my interview with Bill Nighy, it becomes apparent that he hasn’t actually seen the film he is giving the interview to promote. Actually, it doesn’t become apparent at all, he just tells me. He hasn’t seen Their Finest, a second world war-based comedy drama in which he stars alongside Gemma Arterton, because he never watches anything he is in: “God, no.” He thinks he might have seen all of Love Actually, the film that made him a bankable movie star at the age of 54, “at one time or another”, but that seems to have more to do with its ubiquity on Christmas television than any great desire to watch it: last year, ITV3 appeared to show nothing else from about mid-November to the end of January.

Indeed, to hear him tell it, Nighy, now 67, seems to expend almost as much energy avoiding his work as he does actually doing it. “I really, really quite committedly try and avoid it, yeah. It’s hard sometimes because you want to honour the people that you’ve been working with, particularly the director and the writer, but I just find it so dispiriting. And it’s getting harder,” he says, clearly warming to the subject. “In the old days, they’d say: ‘There’s a cast and crew screening on 9 April.’ And you’d just go: ‘I can’t do that, terribly sorry, just can’t make it.’ And they’d say: ‘What a shame.’ And I’d say: ‘Well, I’ll see it some other time’ – like that’s actually going to happen. But of course now, it’s got to a point where they say: ‘Oh, you can’t make the 9th? What day would you like to come? We can set up a screening.’ And then you’re buggered.

Nighy with Gemma Arterton in Their Finest. Photograph: Allstar/BBC FILMS

“It’s not that I don’t like the sight of myself, although I don’t, particularly as you get older, because I remember what I’m supposed to look like. But it’s not that so much. It’s the acting. People say: ‘How do you do interviews if you haven’t seen the film?’ But it’s much easier than if I had seen it. And you know, I was there. I saw it happening. I’ve read the script, I know what the director’s like, I know what happens in it. So I have a perfect relationship with it as far as I’m concerned.”

This, it is gradually transpiring, is a very characteristic Nighy interview quote, in that it is dolorous, painfully self-deprecating and makes rather heavy weather of the business of acting. Get him on the subject of music or clothes and he becomes voluble and enthusiastic. Your entire interview time could be swallowed up by his vigorous defence of Lou Reed’s mid-80s oeuvre. For all he complains about people always asking about his penchant for bespoke suits (“Never in a month of Sundays would I say to someone: ‘But you’re wearing tracksuit bottoms and a rugby shirt with’” – he shudders – “‘the collar turned up, do you want to talk about that?’”), he is quickly lost in a reverie about the clothes he lusted after as a teenage mod in the mid-60s.

But something about his chosen profession seems to bring out the Eeyore in him, which seems strange, given how gilded his career looks from the outside. It began with something of a baptism of fire in the mid 70s. His first London stage roles were as part of Ken Campbell’s Science Fiction Theatre of Liverpool, a company given to staging 24hr-long plays without any rehearsal; his debut National Theatre appearance, in an adaptation of The Illuminatus Trilogy, was further enlivened when the books’ co-author Robert Anton Wilson arrived backstage and started doling out LSD to the actors about to perform, an experience he tactfully describes as “extraordinary”. But in the 80s, he developed close relationships with the West End’s most important playwrights – David Hare and Tom Stoppard among them – and by the 90s he was a regular in TV drama and British cinema. Then came Love Actually. He’s barely stopped working, since, making three or four films a year, carving out a niche in the process. He’s very good indeed in his latest, as a faded British matinee idol called Ambrose Hillard who is offered a career lifeline with a role in a patriotic propaganda film, along the lines of In Which We Serve. Ironically, Hillard balks at the part because it requires him to play against type, while Nighy is scene-stealingly great doing what you reasonably might call The Bill Nighy Thing. While he has played both a closeted gay Welsh miner in Pride and a teleporting pirate with a face-full of tentacles and a crab claw for an arm in the Pirates Of The Caribbean franchise, he has really got the market for absent-minded, irascible, vain-but-ultimately-lovable sixtysomething Englishmen sewn up, which is one aspect of his career that he seems pleased with at least.

“Nothing wrong with doing things you’ve done before. I mean, people used to say: ‘I don’t want to get typecast’ – my big secret was that I couldn’t wait to get typecast. You know, the idea of going to work every day and doing the same thing … man! Wow! That’s like the greatest thing that could happen to me. I have no problem with that. And if there is a thing that people have come to expect from me, I’m very, very happy about that.”

With Felicity Kendal in Arcadia at the National Theatre. Photograph: Robbie Jack - Corbis/Corbis via Getty Images

More often, he tends to present his career in a rather gloomy light. When I ask if he had any trepidation about revisiting his Love Actually role as faded singer Billy Mack for the recent Comic Relief sequel, he sighs and says: “I have trepidation about everything. I literally think: ‘Oh God, now I have to do this?’” Acting, he says, is “an alarming job” that involves “walking on a film set with a number of people and an enormous amount of money and hard work involved and being scrutinised in a way that no human being should ever be scrutinised and not wanting to let anybody down, or going onstage on an opening night when you have people come and put a report in a national newspaper on which the future of the show depends so, you know, no pressure”.

He delivers this stuff in such a deadpan way that it is impossible to work out whether he is slathering on the Eeyore-ishness for comic effect or not. He doesn’t offer so much as a flicker of a smile when explaining the lengths he will go to avoid remembering the horror of “my younger days, when I was less alarming to look at” and was thus required to do sex scenes – “unbearable, a nightmare, like the worst thing that can possibly happen to you” – but nor does he seem to object when I laugh out loud, which I end up doing quite a lot in his company.

But other journalists have disagreed: you don’t have to look far through his cuttings to find someone conflating his glum interview persona with his solitary personal life and deciding that Nighy is a rather dark and troubled soul. He split from his long-term partner, actor Diana Quick, in 2008 and lives alone, in an apparently spartan London flat (“People come round and say: ‘Where is everything?’ And you go: ‘Well, this is everything’ – it looks nice that way”), where he spends his evenings watching football and “Googling Christopher Hitchens or John Lee Hooker or Van Morrison – that’s my basic browser history”.

Nighy (right) in Pravda at the Olivier with Anthony Hopkins (far left), 1985. Photograph: Alastair Muir/REX/Shutterstock

“Oh, people thinking because you spend time on your own, you’re troubled,” he nods. “There’s a thing in restaurants, where you’re sitting there, eating, reading a book, and people think that they’re going to be of greater value than any book can be. They think you’re in trouble because you’re reading: ‘He hasn’t got a friend, poor old sod.’ So they come over and sit with you, which is fine. For a bit. But I’ve actually had to stop using a couple of restaurants, because the proprietor insists on coming and sitting and talking with you, because he thinks: ‘Oh, he obviously needs someone because he’s got a book.’ I mean, I do have friends, for God’s sake. I suppose I spend a bit more time on my own than most people, but I’m very, very accustomed to that. I’m an actor, you spend a lot of time on your own, generally away from home, in hotels and restaurants. I’m perfectly happy. I’m not in any trouble, everybody can relax.”

I have trepidation about everything. Acting is an alarming job

That hasn’t stopped some of his more mournful pronouncements from going viral: in 2015, he said that he thought about death 12 times a day, which became a story reported everywhere from the broadsheets to the Huffington Post to the Wiltshire Gazette and Herald. “Well, I didn’t know it was a news item, but people did start saying to me: ‘Oh, you think about death a lot.’ You go: ‘Well, yeah, don’t you?’ I mean, I presumed everyone did. Twelve times a day was just off the top of my head, I thought that was quite conservative. In fact, it’s probably more than that. Twelve is on a good day. When you get to my time of life, you know, you’re buying a pair of shoes and you think: ‘Oh, I wonder how many more pairs of shoes there’ll be.’ It’s like now, I’m counting springs. You think: ‘Well, let’s make the most of this year’s blossom, because it’s one of the most fabulous things that ever happens, so let’s make sure we don’t miss any of it.’ So if that’s thinking about death …” His voice trails off. “Well, it is thinking about death. And then, if you’ve got a family, you think about doing things that might help when you’re gone. And then there’s always someone dying, which makes you think about death.”

Still, he says, if people think he’s gloomy these days, they should have met him years ago, when his insecurity about his acting talent was “chronic, absolutely paralysing and therefore I had a very unhappy time, a lot of the time, just because of me, because my head was tuned to a bad station”. He is, he insists, quite the ray of self-confident sunshine these days by comparison. So what changed?

“Well, I can still think like that now, unfortunately, but I try to be emboldened by precedent. You know: you did that job and they asked you back, they asked you back twice. Even for me, it’s a bit of a stretch to reinvent that as a problem. You know, it could be a conspiracy to invite me back twice in order to really humiliate me, but I doubt it.

“And eventually, you just run out of that kind of energy. At some point, you just start to think: ‘I can’t live like this any more, this is ridiculous. When do I get to the bit where I realise apparently I’m OK?’ There comes a point where you get too long in the tooth to swallow your own bullshit. That’s my deep philosophical remark for the day.”

Their Finest is released in the UK on 21 April.