Whenever friends approach Séamas O’Reilly for advice on bereavement, figuring him to be a pillar of wisdom on grief having lost his own mother in early childhood, he drafts them the same prescription. “Right, here’s my advice, are you taking this down? Step one: be five.”

O’Reilly’s experience of losing his mother Sheila to cancer in the 1980s forms the spine of his assured debut, Did Ye Hear Mammy Died? The title is born of the phrase that the then five-year-old greeted mourners with at her wake.

“I’d be sticking my hand out to shake their hands, not really knowing the seriousness of what was going on,” O’Reilly says, speaking from his home in Hackney, London. “I don’t remember saying it — the only reason I know about it is because at family get-togethers, it would always come out as one of those go-to funny stories around the kitchen table.”

Did Ye Hear Mammy Died? is singular in tone, occupying a sweet spot between the tragicomedy of Frank McCourt and the pin-sharp observational humour of David Sedaris. Much of this comedic heft comes from the fact that O’Reilly was the ninth of 11 children: not unusual once upon a time in Ireland, but in 1980s Derry it was borderline radical.

“People have just literally pointed to me at a party or at a dinner table and gone, ‘He’s got 10 siblings’,” O’Reilly says. “The thing I really want people to understand is that we never thought it was normal. We were constantly making fun of ourselves.”

Certainly, the O’Reillys were a well-known sight in the area, being ferried about in the family minivan by their indomitable father, Joe. O’Reilly’s readers are likely to fall hook, line and sinker for Joe as a character.

Affectionately sketched by his son, Joe takes magnificent delight in killing rogue mice that invade his house, yet is a known pillar of Christian goodness within the community. Whatever time he has left over from rearing 11 children single-handedly on one wage, he uses by helping others and curating arguably Derry’s most impressive home-VHS collection, complete with categorisation and viewer notes; a sort of proto-Netflix.

“Sometimes he literally seems like he’s just landed from medieval Prussia, with no cultural awareness of anything,” O’Reilly says. “I realised once that he’d never heard of Rock, Paper, Scissors. I mean, he’s younger than Paul McCartney.”

O’Reilly, himself a father-of-one, still marvels at his Joe’s considerable parental load, though of course Joe himself will have no truck with that. “At one point he had six teenage daughters,” O’Reilly says. “I mean, I can’t imagine what that was like, and I was literally there.

“We’d always ask him, ‘Why did you have 11 children,’ to which he would always say, ‘Well, which of ye would I give back?’ which is a very sweet, Sunday-school thing to say,” O’Reilly adds. “Except we’d then immediately suggest a few that he very much could.”

Laugh-out-loud funny

The 11 children were aged between two and 17 at the time of Sheila’s death, and have always been categorised within the family as The Big Ones, The Middle Ones and the Wee Ones. “It wasn’t so much tribal as it was a caste system,” O’Reilly says.

“We inhabited different legal and human rights jurisdictions. Hopefully from this book will come the subsequent tribunals, then maybe a moment of peace and reconciliation.”

O’Reilly’s recollections are laugh-out-loud funny, yet the delicate dance between light and shade is the book’s true power.

“That’s the way I processed grief, and the way my family has, by finding the moments of humour and laughter,” O’Reilly says. “They’re very therapeutic for one thing, and secondly, it’s true to life.

“I was also aware that there’s this other strain of literature, more broadly, that might be termed as the ‘Irish miserable childhood’. And when you read them, you think, ‘God, was there no-one there cracking a joke?’”

O’Reilly’s grief process has clearly shapeshifted over the years, and he now finds himself occasionally struggling with the ‘shame’ of it. “I did not experience the same grief as other members of my family, or friends who have been similarly bereaved, because it happened before I was able to understand it,” he writes. “I had muddled through the shallow understanding of grief my five-year-old self could manage, and when the collective tears died down, I told myself the job was done,” he writes.

“I’d buried it, out of fear and shame and an inability to know how and when to grieve for myself.”

For years, O’Reilly’s impression of his mother — a former nurse who was every bit as sweetly altruistic as Joe — was largely informed by the effusive accounts of others.

When he started writing the book, O’Reilly had just “five memories written down in a spreadsheet”. The process of writing somehow helped him unearth three more.

“It was like I was performing some sort of magic trick on myself. That was wild,” he says.

“I remember a friend telling me that a friend of theirs, their partner died and they had a young child, and again they were asking me for advice. Obviously, I can’t speak to that experience, but I said, ‘Here’s maybe something. I would say, for those kids, write down every memory that you have of that person as much as possible’.

“I’ve discovered letters that my mum sent to my auntie Patricia, and even though there are all these incredibly mundane details — like driving to the shops in Enniskillen — they’re worth their weight in gold.”

O’Reilly recalls being the ‘dork’ of the clan, “like the kid character in Jerry Maguire, but without the movie star good looks. I’d just go around haranguing you with facts. I would just hang off people,” he recalls. “I wanted to impress people and wanted people to notice me, because obviously I was suffering with this horribly diluted amount of attention.”

O’Reilly had always liked the idea of being a writer, and soon he took his humour and convivial writing style to a place where it would immediately be recognised: Twitter.

In 2018, O’Reilly replied to a tweet asking about ‘work related f***-ups’ with a thread that went viral. It began with ‘got my days wrong and ended up alone in a room with my boss and the President of Ireland while I was on ketamine’, and only got more hilariously surreal from there. He was 18 at the time, working as a waiter while in college in Dublin. Mary McAleese was the president in question.

“I’ve heard [from various people] that the thread was shown to her quite a lot that weekend, but I’m sure bigger, more exciting and more newsworthy things happen to her on a daily basis, than, say, trending on Twitter for like 45 minutes.”

The thread gained him instant attention, and the Observer eventually offered him a column in which he writes about his parenting experiences. Given that he was working a thankless desk job at the time, he leapt at the chance to write full-time.

Book offers followed in hot pursuit. Having written for years, O’Reilly was more than ready with a manuscript. He signed with Fleet, which O’Reilly proudly mentions is also the home of Colson Whitehead and David Sedaris.

He is working on follow-up material — this book ends with him at 11, so his adolescent years could very feasibly be mined in the future. O’Reilly is about to record the audiobook, but has already read the book to an important audience: his father. O’Reilly read it aloud as his father’s eyesight “isn’t great” because of his diabetes.

“It’s an incredible experience to be able to read a book you’ve written about a person to that person,” he says. “He was moved at places where I was expecting, and he even managed loads of corrections, like the length of vehicles that were mentioned.

“I’m sitting there, reading and sweating buckets and I’m getting all emotional, and Daddy goes, ‘Actually, that’s not the car we had in 1991’. But he knew that it was his story. And because of that, it’s very much my story.”

‘Did Ye Hear Mammy Died?’ by Séamas O’Reilly is out now from Fleet