There is a short video on YouTube of Gabriel Byrne being interviewed by the Irish comedian and actor Tommy Tiernan. “Do you think you’re a strange man?” asks Tiernan. “I do think I’m a strange man, yes,” replies Byrne without hesitation. He then bats the question back to Tiernan, deftly sidestepping any further discussion of the subject. I ask him if now he could elaborate on the nature of his strangeness.

“I like to think I’m pretty normal and not given to extremes, but people who know me well would probably think I’m a little strange,” he says. “It surprises me when they do, but, of course, an eccentric does not know he’s eccentric. So, yes, maybe I am a bit strange, but not in the sense that I’m weird.”

As an interviewee, though, Byrne is, if anything, the opposite of strange, coming across as genial, thoughtful and articulate. From time to time, though, there is a palpable intensity to him and a sense that, as the title of his recent memoir, Walking With Ghosts, attests, he is still haunted by the past. It is most evident when he talks about his upbringing in working-class Dublin or describes the religiously repressive and parochial nature of the society he fled when he emigrated to London in the late 1970s. “To be honest,” he says, “it’s only lately that I have begun to reconcile myself to Ireland, and to myself when I left there. That has not been completely healed.”

In 2010, on an Irish television programme, Byrne revealed that he had been sexually abused by Christian Brothers as a young child and again, by a Catholic priest in the seminary he attended in Liverpool, aged 11. “The priest’s breath was sour and hot as he moved toward me,” he writes in recollection of that terrible transgression. “Then there was blackness.”

In advance of the interview, Byrne stipulates that he no longer wishes to talk about those bleak times or about his later descent into alcoholism in the 1990s – “I’m just tired of discussing these topics” – but he has much to say about the ways in which a traumatic past can determine the present.

“It’s hard to believe we came out of that universe,” he says, when I tell him I too was educated by Christian Brothers. “They dealt in fear and humiliation. Some of that goes deep inside you and takes a long time to get rid of – the fear of the world, the uncertainty of life and your place within it. And the humiliation of it all, which is akin to shame.”

In many ways, his memoir reads as a kind of exorcism of that long-carried fear and humiliation. On the page, his life before and after fame is told through a series of tangentially linked, often deeply revealing, vignettes, the narrative constantly shifting back and forth across time and place. “I wanted to capture how memory actually works,” he says, of the fragmented, non-linear structure. Next month, when he starts touring his stage adaptation, it will unfold chronologically. Shorn of its more descriptive passages, the production depends to a great degree on Byrne’s ability to make a recalled world come alive on a spartan stage.

“Put simply, what is suitable for a book is often not stage-worthy,” says Lonny Price, the veteran Broadway director (Camelot, Sunset Boulevard, Sweeney Todd) who has collaborated closely with Byrne on the production. “There are large chunks of the book I love that are not in the play, but there is some new stuff, too.” Price describes the production as “essentially very simple: a table, a chair, a bench and a table – it doesn’t need anything else, because it’s all about Gabriel and he does not need any help to hold the stage. The material and the acting are enough.”

Earlier this year, Walking With Ghosts debuted at the Gaiety theatre in Dublin. I ask Byrne what it was like to walk on stage in his home town for the first time in more than 40 years and essentially lay bare his young life there. “Of course, I was nervous – I’m never not nervous – but this was different. I’m not sure what I can compare it to. It’s like if somebody asked you for a bet to take off all your clothes and walk down Shaftesbury Avenue. Very slowly. Now, of course, you can do it, but that’s not the point. When you reveal yourself on stage, it’s like you’re kind of taking your clothes off in public.”

* * *

I am talking to Byrne on a Zoom call to Budapest, where he is filming the final scenes of a biopic of another famous Irish exile, the playwright Samuel Beckett. The film’s working title is Dance First, which refers to a phrase in Beckett’s most famous work, Waiting for Godot – “…dance first and think afterwards”.

Directed by James Marsh, who made the Oscar-winning 2008 documentary Man On Wire, and also starring the French actor Sandrine Bonnaire, Dance First concentrates on Beckett’s life and relationships rather than his plays and novels. Byrne plays the enigmatic, intensely private writer in old age. “It’s an attempt to put flesh and blood on someone who people know very little about,” he says. “He was a man who had a sense of humour, who was deeply emotional, who was a failure in his own eyes for a great deal of his life, then had to contend with world success after being given the Nobel prize, and who lived the last part of his life alone in a very simple room in a nursing home.”

Byrne, now 72, bears only the slightest resemblance to the gaunt, bird-like Beckett, who died, aged 83, in 1989. “Physically I can sketch him,” he says, “but with this film we are not looking for an impersonation of Beckett, rather a sense of who he was. What you want is people to believe the man, not focus their attention on the wig or the makeup or the false nose.”

Given that Byrne is also an accomplished stage actor, who has twice been nominated for a Tony award for best actor for his performances in two Eugene O’Neill plays, A Moon for the Misbegotten (2000) and Long Day’s Journey Into Night (2016), I wondered if Beckett was in any way a touchstone for him.

“The interesting thing is, before this film came along, I was curious about him as a literary figure, but I never found him to be an emotional writer. Likewise Pinter. I thought that, in their work, the emotion was subsumed to the writing itself. Then, I started to read Godot for this part and I thought: ‘My God, this is actually really funny! It’s about real emotions – loneliness, connection, friendship.’ I had missed all that, mainly because I had never seen a good production of the play. I saw Robin Williams and Steve Martin do it in New York and it was awful. Anyway, I’m now converted.”

Later, when I ask Byrne if he is, as his own writing suggests, essentially a romantic, he says: “I’m caught between a Beckett view of the world and the romance and the joy of living. There’s a fair sprinkling of Beckett in there, but I guess I am a romantic.”

His friend, the actor Richard E Grant, who directed Byrne in his semi-autobiographical film, Wah-Wah, tells me: “Gabriel is the most philosophical person I know, forever seeking and questioning everything, so much so that I don’t recall him ever finishing a plate of food, as he gets waylaid by what he’s thinking and talking about.”

Grant also attests to the depth of their friendship. “During the final months of my wife’s life he regularly visited us whenever he had breaks while filming in Wales. Regaling her with anecdotes and stories that cheered up her spirits beyond all measure. A true friend.”

Offscreen, Byrne lives a relatively quiet life in Rockport, Maine, with his wife, Hannah Beth King, and their daughter, Maisie. He has two grownup children from his previous marriage to the actor Ellen Barkin. “I didn’t have that many complaints about LA, but it’s a factory town,” he says. “That’s essentially what it is and I just got tired of talking about movies constantly – what this person is doing or that person is doing. Where I live now is very far away from that in every way.”

Is Hollywood a radically different environment post-Harvey Weinstein and the rise of the #MeToo movement? “I think the question is bigger than Weinstein and it’s bigger than Hollywood. It wasn’t like he was the only one and Hollywood was the only place. Exploitation and abuse of power goes on, to a greater or lesser extent, in every town and every village in the world. It’s been going on for ever. There are Weinsteins who are not famous, whose behaviour goes from inappropriate to being criminal, but we tend to look at Hollywood and say: ‘Ah, it’s all over there.’ But, by and large, most people that I knew in Hollywood were sober, workaholic, ambitious people.”

Along the way, Byrne’s Dublin accent has softened into a transatlantic brogue, but otherwise he appears relatively unchanged by the celebrity that comes with his calling. “I honestly don’t think about it that much,” he tells me “and it doesn’t bother me that much, either, but I do find it uncomfortable. I’ve always been uneasy with it. I don’t like all the trappings. I hate red carpets. I hate photographs. I’m not comfortable on chatshows where they ring you up and say: ‘Have you got a funny story about this new film you’re in?’”

* * *

As Walking With Ghosts attests, Byrne has a surfeit of funny, as well as surreal, and sometimes painfully self-revealing stories, not just about the films that have made his name (Excalibur, Defence of the Realm, Miller’s Crossing, The Usual Suspects) and the stars he has worked with, from Richard Burton to Leonardo DiCaprio, but also his eventful life before he became an actor. As a boy, he trained for the priesthood in a Catholic seminary for five years, before working variously as a plumber, dishwasher, toilet attendant and, having returned to college, a schoolteacher. He came to acting, aged 29, “almost by accident”, joining a local theatre group in Dublin on the advice of a friend, before landing a part on The Riordans, a popular Irish TV soap opera about rural life. He was cast, he writes, “as a kind of Irish Heathcliff” and, to his mortification, became a sex symbol in Ireland. To this day, he hates the word “brooding”, which has been most often used to describe his good looks.

“I honestly didn’t foresee myself going into acting,” he says of that time. “I was a teacher for nine years, English and Gaelic, walking around with a gown on me and a pile of books under my arm. It was a job with great summer holidays and the prospect of retiring at 50. Back then, I thought, this is my life, and it was a life I didn’t mind living at all.”

His fragmentary memoir brilliantly evokes a Dublin of larger-than-life characters and working-class experience that has all but disappeared, but it is also, I suggest, an acute delineation of the exile’s dilemma of not belonging. “That’s very true,” he says, nodding. “When you leave the place to which you belong, which I did, you leave behind your essential self in many ways. You have to join the culture that you have gone to and, in doing so, shut down that other part of yourself, that deep connection with home. And, after a while, you also realise that you can’t go back. There is no return. You become someone who is not truly at home in London or New York, but not truly at home in Dublin either.” He pauses for a long moment. “You have to make peace with that or you’ll be tormented forever by the question – do I belong here, or do I belong there?”

Byrne tells me that he felt “utterly lost” when he first arrived in London in the late 1970s. He joined the Royal Court in 1979 and, in one of the more visceral scenes in his book, reveals how, after one performance there, he was badly beaten up by drunken British squaddies while waiting for a taxi on the street outside the theatre with his girlfriend. The young soldiers had just returned from a tour of duty in Northern Ireland and, hearing his accent, had taken umbrage.

“It was a particularly turbulent time politically,” he says, “and I don’t think the English knew what to make of Irish people. There was a sense that we could be laughed at, all the anti-Irish jokes and so forth, but that they also feared us because of what was happening with the Troubles.” Were those attitudes apparent, though, in the theatre world? “Well, when I came over as an actor, I was never not conscious of the fact that I was Irish. Not for a moment. In auditions, you were often immediately characterised by how you spoke and offered filler roles – the Irish drunk, the Irish terrorist, the wily sleveen [untrustworthy] character. The idea that you could do anything else besides that was curiously not in the minds of the people who cast you.”

In 1983, living in a grotty flat, and having spent 18 months unemployed save for a single role in a BBC play, Byrne was thinking of giving up acting when he landed a small part in a British television mini-series, Wagner. It starred Richard Burton in the title role and was being filmed on location in Venice. Suddenly, his life was turned upside down. “I was so unused to being on a plane,” he writes, “that I took photographs of the wing.”

He befriended Burton over nightly drinking sessions on the terrace of his hotel room overlooking the Grand Canal. Sipping expensive brandy, he listened in awe as the older star offered advice on fame – “It doesn’t change who you are, it changes others” – and acting: “Give it all you’ve got, but never forget it’s just a bloody movie. We’re not curing cancer.”

I ask Byrne what he considers the other pivotal moments in a career that has seen him appear in more than 70 films. “Well, my role in Defence of the Realm certainly, which was a pretty accurate depiction of what a journalist is up against. A guy goes to tell the truth and the powers that be eliminate him. I thought it was a brave picture for the time, but it also changed my career. When it was released in America, it led to Miller’s Crossing with the Coen brothers, and that definitely changed things. In terms of theatre, it was Moon for the Misbegotten on Broadway.”

For someone who was blessed with film-star good looks, Byrne has always been an understated actor who specialises in suggestion and nuance. “I’ve always believed in simplicity,” he says. “In the theatre, you do have to give it a bit more because it’s live and you need to reach the people at the back. Film is different. Somebody once said the camera can record what you think. That’s an interesting idea. So, yes. I tend to be low-key. I’m not a great fan of big gestures and displays of emotion unless they are actually called for. In real life, we don’t betray ourselves in that way except for some really extreme emotional moments.”

His understated approach underpinned his acclaimed portrayal of psychotherapist Paul Weston in the hit HBO series In Treatment, which he describes as “maybe the most difficult thing I’ve ever done”. Over four series, it required him to do what psychotherapists do best, which is listen.

“Listening on screen is a very particular form of acting,” he says, “just as listening in life is a very interesting thing. You know when somebody is not listening, or fake listening, or listening and hoping that you’d just fucking finish up. Just as you always know when people are truly listening and really connected.”

He prepared for the part by surreptitiously observing people in cafes while they were engaged in deep conversation. “It’s a very moving thing to just sit in a restaurant and watch people talking to each other. That’s actually how I got the key to the character. I saw two people in a cafe absolutely absorbed in listening to each other. The listening was the drama.”

In Walking With Ghosts, he recalls with brutal honesty the bouts of melancholy he occasionally fell into and a long moment of existential terror that beset him when The Usual Suspects became the hit of the 1995 Cannes film festival. As he was ushered past the paparazzi into a celebratory party, he describes how the “tumult” raging in his head became so overwhelming that he thought he might “fall down and be found weeping in the street”. While his co-stars celebrated, Byrne fled to nearby Nice and took to his hotel bed for several days, “unravelling inside… and without even a spark of hope”.

Reading his searingly honest memoir, it is hard not to make the connection between this moment of psychic breakdown and the then-buried traumas of Byrne’s childhood. He seems blessedly to have rid himself of many of the ghosts that haunted him. When I ask if he has any regrets, he thinks for a while and then says: “I regret that I didn’t shake off the inculcation of Catholicism and the rigid class thinking of Ireland sooner. To a great extent, those experiences crippled me in terms of my self-esteem and my self-worth. For a long time, I felt ‘Who are you to be even thinking you deserve anything? Who are you to be happy?’ I wish I’d thrown off those shackles earlier, because it would have given me a certain freedom, but I am at a place now where I am free of that kind of thinking. I embrace the idea of change unreservedly.”

In his more Beckettian moments, does he worry at all about encroaching mortality? “I used to have this foreboding about it when I was younger,” he replies, “but, funnily enough, that has gone. One of the things I realise as I get older is that part of reconciling oneself to life is the acceptance that we lose everything, we lose parents, we lose friends, we lose jobs, we lose houses. And eventually we get to the stage where we lose ourselves. In the end, we are all losers. You just have to accept that.”

• Walking With Ghosts will be at National Opera House, Wexford, 12-13 August; Edinburgh international festival 24-28 August; and the Apollo theatre, Shaftesbury Avenue, London W1, 6-17 September

• Walking With Ghosts by Gabriel Byrne is published in paperback by Pan Macmillan (£9.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply