Children of war who John Boyne can't leave behind...
It's tormented some of history's greatest, inordinately fluent writers, from Tolstoy to Conrad, Hemingway and Woolf. A notorious culprit for a temporary cessation of words.
Author John Boyne, however rejects, the idea of writer's block. Nor does he have the time.
"I don't believe in it," he pointedly responds. "If you're feeling [blocked], put down a sentence and see where it takes you.
"Some days it'll take you nowhere, some days it will take you through a few pages. I don't want to wait for the muse to strike.
"And I really feel, and I know this sounds strange as a person who's already written so many novels, but I've so many more stories to tell.
"And life is moving on. I've a lot more I want to write."
It doesn't so much sound strange, as pathologically industrious. Not that it's done Boyne any harm.
Twelve novels in 14 years, published in 46 different languages.
Internationally, over five million copies shifted of his most lauded title, Holocaust fable The Boy with the Striped Pyjamas, which became a major motion picture, pushing the Sandyford native into the UK and Ireland's book trade Millionaires Club - only the second Irish author after Cecelia Ahern to move over a million units of their work.
His stories have traversed eras and significant events across the historical annals - dusty Wild West escapades with Buffalo Bill (The Congress of Rough Riders); treachery on the waves alongside Captain Bligh (Mutiny: a Novel of the Bounty); emotional embattlement amongst the trenches of the First World War (The Absolutist).
He's immersed readers in the fall of the Romanov dynasty (The House of Special Purposes) and the abdication of King Edward after the Wallis Simpson affair (Next of Kin).
Clearly a novelist who eschews the foundational notion - write about what you know.
"It's one of those tired old cliches. I find it more interesting to write about what you don't know."
After The Absolutist, however, he found himself keenly knowledgeable on the horrors of WWI and latest release, Stay Where You Are and Then Leave is his first return to a visited period.
"Usually I want to move on from that part of history, but that novel stayed with me and after I did all the research, I felt there were a lot more stories I wanted to tell."
A majestic children's tome, Stay Where You Are recognises the ravages of The Great War through the eyes young Londoner, Alfie.
Kind and meddlesome, with a healthy grasp of bon vivant - much like Stripped Pyjamas' tragic Bruno - he watches as his father's caught up in the excitement of impending battle on the front line and returns a profoundly changed man.
"I hadn't really touched on the issue of shellshock in The Absolutist and was planning on writing a new children's book. So I thought maybe I could take this subject forward and connect them in some way.
"So I immersed myself in letters written between soldiers and their families from the Imperial War Museum in London.
"It was this tone I tried to use in how Alfie's father writes to him and how his own speech patterns change from when he's a young man going off to war, through the war and then when he ends up in hospital. And then how this severe case of shellshock frightens and confuses his young son."
His fourth children's book, John admits these immature protagonists are loose projections of his own youth. "Their sense of optimism and positivity about the world and trying to be older than they are. A lot of that goes back to who I was as a nine year old."
His next title, A History of Loneliness, is his first to be based in Ireland, finally answering critics who groused Boyne's lack of home-based literature.
Released in September, it surveys the state of the Catholic Church, from its autocracy in the Fifties to the current shattered existence after decades of heinous allegations, all witnessed through the eyes of one priest.
"I didn't want to write about Ireland until I had a story that would say something about the country," the author explains. "Everybody's writing about the banks, seem so tedious to me.
"And the abuses in the Catholic Church, it's a subject which Irish novelists seemed to have steered away from."
Protagonist Father Odran Yates is a good man, dedicated to his vocation yet haunted by the wrongdoings he possibly turned a blind eye to.
"He's not an abuser. He's done his best to help people. But he begins to realise the way he's lived his life, perhaps he has been complicit."
Boyne spent 18 months interviewing members of the clergy and discovered a calling in turmoil.
"There seems to be a real sense of denial. Perhaps because you devote your life to something that turns out to be not just flawed but entirely corrupt.
"And I heard some very interesting stories from good priests and how they're approached from society now. The issue that some won't wear their collars when they go into town because people will look at them funny. Or spit at them."
Ultimately, he hopes to present a balanced counter, rather than a largely biased approach.
"I'm not trying to do a hatchet job."
Stay Where You Are and Then Leave is out now