The Heart's Invisible Furies is a very moving, often funny book about a gay man's life across seven decades of Irish history. It made me cry, I tell its author.

"Then my job is done," John Boyne says, a neatly dressed, bespectacled man with a shaved head and 16 books to his name. "There is the intellectual writer and the emotional writer, and I am an emotional writer . . . I want people to be moved. I don't want people saying, 'That was very clever'."

Boyne always wrote. “From the age of nine or 10, I used to take characters from existing kids books and write new stories for them. I did a lot of plagiarising. Remember Bobby Brewster? Did you ever read those as a kid?”

I shake my head and he sighs. "Nobody remembers Bobby Brewster. He was just this kid and magical things would happen to him. Inanimate objects would come to life around him. HE Todd was the author."

What sort of child was John Boyne? “Solitary, lonely, bookish, nerdish,” he says. “I wasn’t good with social situations. I wasn’t particularly good with other kids. I was kind of a cliche in a way, the kid sitting in a library with glasses on, reading a book and finding peace and safety there. And I kind of still do in a way. Not necessarily in a library, but I like the safety of books.”

Vulnerable children and unreliable parental figures are a bit of a theme in Boyne’s books. “I know,” he says. “It’s a theme in almost all of them. It’s strange because that’s not the family I grew up in. It was a very connected family.”

He describes a solidly middle class, south Dublin family with an insurance broker father and a stay-at-home mother who brought him to a library every week. “As I grew older and went to Trinity and UEA [University of East Anglia], they certainly encouraged me,” he says. “There are always the people who say they want to do something, but they’re not doing anything about it. I was actively writing, so I think they were encouraging of that.”

In Trinity Tales, a recent book of essays about TCD by alumni, Boyne's contribution is devoid of any rose-tinted nostalgia. "I just found it very uncomfortable to be thrown into that lion's den of sociality. I lacked all confidence. I don't know why and it took me years to develop it. So I don't remember [Trinity], I don't have great stories to tell of my time there or great memories."

Sole ambition

Boyne wrote all the while. The confidence Boyne lacked socially he seemed to find on the page.

“From the age of 16 or 17 my sole ambition in life was to get published, to be a professional novelist. It was just instinctive. I loved books, but I didn’t just love them as a reader. I wanted to be part of that world. I liked playing with words. I liked inventing characters. And I believed I was good at it and getting better at it all the time. There was no back-up plan. No plan B.”

He got on the creative writing MA in the University of East Anglia (he later set up a scholarship programme for Irish writers who want to go there). He also wrote a couple of "personal novels about me and about Ireland" which were never published and which he hasn't read since: "They sit there and when I'm dead they can do a Harper Lee on me if they want."

Boyne eventually mined a solid seam of historically-set novels about people who were nothing like him. He has, over the years, written books about revolutionary Russia, murders in early 20th-century London and mutineers on the HMS Bounty. And he eventually alternated these with similarly high-concept books for children.

“I see them as the same thing, really,” he says. “I used to say, ‘I write books for adults and for young people’. Now I say, ‘I write books about adults and books about young people’. I prefer to think of it like that.”

Why did Boyne never write about Ireland in those days? "I found that my imagination was taking me away from Ireland rather than into it. That expectation isn't forced on English writers or American writers. They're given the freedom to write about whatever they want, so I don't see why Irish writers have to write about Irish subjects.

“In many ways, I think Irish writers are too insular and there’s a big world out there. And I don’t think that we should have to write about farms in Roscommon.” He laughs. “Not that there’s anything wrong with writing about farms in Roscommon.”

Creative environment

Boyne's first books were published while he was still working in Waterstones 17 years ago, alongside fellow novelists Paul Murray and Sarah Webb with whom he is still friendly. "It was a young, creative environment, a very happy time actually," he says. "It was a very different Irish literary world then. There weren't as many writers, and everybody was working individually without reference to each other."

Does he think that that’s changed? “Let me phrase this correctly. The Irish literary world today is much more concerned with collectives and people being part of a group. I think it’s a mistake as a writer to associate yourself with other writers or with a movement or any cultural identity. Writers should work alone. They should certainly be supportive of each other, but I think it can be hard to distinguish between books right now because some authors are coming at it from a very board-like identity.” He grins and adds: “‘He said carefully.’”

Around the time he finished working in Waterstones, Boyne had an accident and fell into a period of depression. He has spoken about this before, but he doesn’t want to do so today: “I feel like I’ve talked about that a lot.”

He is happier discussing what happened a few years later – the overwhelming success of his first children's book, The Boy in the Striped Pyjamas (2005), a story about children during the Holocaust, subsequently made into a Hollywood film.

“I will never write a book that is read by as many people,” Boyne says. “It’s a book I’m really proud of and grateful for. It gave me financial freedom, an international audience and the life I have today. There are people who have a success like that and then want to disown it. I’m not one of those people. I don’t want to spend my life talking about it, necessarily . . . but it was an amazing few years of my life.”

Admittedly, there were also times when it was overwhelming, he says.

“I’d become this unofficial spokesman for something, and at times I wondered whether I had the right to be the spokesman. I went to a lot of Jewish community centres in different countries and a lot of Holocaust centres and memorial museums, and I would often meet Holocaust survivors and feel nervous. The general feeling among survivors seems to be as long as people are writing about it and talking about it and making films about it, that that was a good thing.”

Right to write

There was criticism (not from Holocaust survivors, he stresses) on whether a young Irishman had a right to write about such a subject. “But I always say that that’s okay. You should be able to have a debate about literature. I don’t need people to love everything. I’m perfectly happy for someone to say I don’t like your book and here’s why and have a conversation about it.”

The wider literary conversation is important to Boyne. He writes book reviews for this paper and he has strong feelings about it.

“I like writing reviews. Especially if you can review something that you think is really great. But I don’t think I could write about an Irish novel anymore – you’re not allowed have a negative opinion. Even suggest that an Irish novel isn’t the greatest piece of writing in the known universe and you’ll be dragged out of town on a cart. It’s exhausting.

“It doesn’t do the writers any good and it doesn’t do the readers any good, having the same people writing the same things about books that are often difficult to tell apart from each other. Save your praise for something you really admire, not your mate you play football with on a Friday night.”

Is it painful to get a bad review? “Yeah. It is. I have to suck it up. I’ve given enough of them. The worst part with a bad review is if you realise they’re right about something. Some writers say they don’t read reviews. In the olden days that was a lot easier to do; you just didn’t buy the papers. But with the internet, it’s very difficult not to be aware of them.

"John Banville says if you've got a bad review you can rely on your best friends to phone up to make sure you've seen it. If I get a terrible review of this book, 10 friends will text me to say sorry about that review." He laughs.

Home themes

Boyne has never been afraid to deal with big subjects, be it the Holocaust, war, clerical sexual abuse or, with the new novel, sexual identity in Catholic Ireland. Still, it seems the themes are coming closer and closer to home. A History of Loneliness (2014), which delved into clerical abuse, was the first of his novels to be set in this country, but Boyne thinks the biggest change came with the one before that, The Absolutist (2011), which is partly set during the first World War.

“It was the first novel I wrote which had a gay character at the centre of it. I was bringing my own experiences and my own life into that novel. I was beginning to be more introspective and personal.”

The Heart's Invisible Furies charts the life of a gay man named Cyril Avery through the homophobia, violence and repression of mid-20th-century Dublin, into exile in Europe and America, to back to post-marriage referendum Ireland. Why did he write it?

“I dreaded the idea of a referendum,” says Boyne. “We weren’t going to be able to turn on the television or the radio without hearing people it doesn’t affect in any way with their hate speech. I dreaded it and it led me to thinking about Ireland and how Ireland had changed, and I thought I’d like to write about Irish society and gay people and how they have been treated.

“I thought it was the right time for me to write a story like that, and I felt I was the right person to write it.”

The novel ended up being both funny and redemptive, which surprised him.

"The day that the referendum was on, there was an RTÉ news report where a 90-year-old came out of a polling booth crying. And the interviewer asked why he was crying, and he said, 'Because it's too late for me'. When I started writing, I thought it was going to be about an old man who had never found love, looking back over his life. But then when I started writing the jokes started to come."

Without the humour, Boyne adds, “I don’t know if I’d have got away with a story like this over 600 pages”.

What’s the point

Did the referendum affect him as much as he feared? “I made one mistake, I think. And that’s engaging with strangers on Twitter. They’re not going to agree with you any more than you’re going to agree with them, so what’s the point in arguing with them? I just couldn’t understand how people in Ireland who were not gay, who were married with children, could be so bothered by gay people getting married.

“What gay people were saying was, ‘We respect the institution you’re in so much that we want to be part of it’. I don’t see how another person’s marriage can be so unstable that two complete strangers engaging in the same activity would rock it.”

The novel’s Cyril Avery also argues with people on the internet. He is, Boyne says, the character he has created that is most like himself. “He’s fairly light-hearted. He tries doing the right thing. He keeps making mistakes. He keeps falling in love with the wrong people.”

He laughs. “I wish I was more like Julian,” referring to Cyril’s sexually confident best friend and unrequited love. “There have been a few Julians in my life.”

Does Boyne think of Cyril’s generation of gay men and think, ‘There but for the grace of God’?

“A little bit. And I also look at 17-year-old gay people now and see them being totally open about who they are. And I look at them with delight, but also envy that I wasn’t as confident at that age.” He smiles. “But such is life.”

Did the younger John Boyne ever think he would write about sexuality in Ireland?

“In my 20s, it was something I wouldn’t have felt comfortable writing about. But I’m not in my 20s, and don’t have the hang-ups I had then. I came out when I was 22, but I wasn’t running up and down the streets dancing and singing about it to everyone I met. It would have taken me a while of knowing someone before I could confide in them something that I would have seen as slightly shameful and embarrassing.

“Now I wouldn’t care. And I wouldn’t allow myself to be disrespected in the way I might have done when I was 22.”

A very thin skin

Is Boyne more in touch with his own emotions now?

"Oh God, yeah. I'm one of the most emotionally tuned-in people there is. I'm too emotional, to be honest. I'm very easily hurt and I have very thin skin, not in a Donald Trump kind of way, but thin skin in that I'm not good at dealing with negative things in my life. I don't think I'm very strong person when it comes to emotional things. Maybe it's why I'm a solitary writer. I don't have a wall around me that lets insult or hurt bounce off me."

He says he is content with his position in the Irish literary world – “not a young firebrand, not quite an elder statesman, just a mid-career hard-working writer”. What about a life outside the profession? “Oh I don’t really have one,” he laughs. “I travel a lot, mostly for work. I like meeting other writers; I like meeting readers. In general, my days are taken up with reading and writing. I play piano and I play guitar. I have friends. I’m content with the life I have for the most part.”

The story of Cyril Avery is ultimately very uplifting . Boyne discusses two of his other recent books (I’ve redacted which ones so as not to spoil them), in which the protagonists end up lonely and bereft or shooting themselves.

“In this book I didn’t want that. I felt very clear in my head that he was going to end up happy. Cyril is going to learn, just like the country learns . . . It just seemed natural to me that he was going to be content.”

From suicide to loneliness to happiness: that feels like a positive trajectory. “Yeah, they’re getting better and better,” he says and laughs. “The next one will be about a dancer or something.” Later, however, he says: “The ending can’t be happy or sad just for the sake of the reader. It has to be truthful.”

The Heart's Invisible Furies is published by Transworld Ireland. http://johnboyne.com