The reason we love Noises Off, he avers, is to do with the feeling we all have that things might go wrong at any moment. “But we keep that [feeling] below the level of consciousness,” says Frayn. “So it can be nice to watch other people struggling to keep chaos at bay.”

I ask him which work he’d most like to be remembered for, expecting him to pick Noises Off, or Copenhagen, or even his Whitbread Prize-winning novel Spies (2002). But without hesitation, he plumps instead for My Father’s Fortune (2010), a moving account of his wartime childhood in Surrey, full of memories of his mother and asbestos-salesman father, Vi and Tom.

He relives one of the most memorable incidents in the book: the night one of the first doodlebug bombs came directly overhead then exploded near their house. “It brought down the ceiling, and blew in all the windows. None of us were injured but it killed everyone in the house beyond,” he says. “It must have been awful for my parents, dealing with the mess, but being children it was quite fun – lots of twisted window-lead to melt and make things out of.”

A year later, in 1945, tragedy stuck when his mother died of a heart attack; he was just 12. Some of the most poignant lines he has ever written concern the way he and his sister, Jill, were kept away from the funeral, and how his mother was never mentioned again. (His father remarried in 1949, and died in 1970):

We had had a name for her when she was alive, of course. We had called her what most English children call their mothers. Somehow, though, we could no longer say the word. I’m not sure I can even now, even to myself. I’m not sure I can write it down … Yes. She was Mummy. It was Mummy who had died. There – done. For the first time in sixty-four years…”

Did brushing so much under the carpet cause anger? “No. I think children then accepted that a lot of things in life were closed to them, that they were to be disciplined in lots of ways,” he replies. “It didn’t occur to one to ever challenge it, to say ‘Why can’t I go to the funeral?’”

Last time I spoke to him, he reflected candidly on the what-ifs around that death: “I think if my mother had lived I might have had a more straightforward life, passed all my exams, got a job somewhere. I probably wouldn’t have tried writing, it’s very difficult to know.”

Today I mention something Eddie Izzard, whose mother died when Izzard was six, told me – “There is an underlying thing that if I do enough good and positive things, Mum will come back…” Does that idea resonate with Frayn? “I do like to have the approval of audiences and readers,” he replies cautiously. “But I can’t consciously connect that with my mother’s death.” That “consciously” seems telling even so. Why did he never do Desert Island Discs? “I thought I would get too emotional.”

“It was as if a volcano had erupted in our lives and the tremors reverberated for years”, his daughter Rebecca has said of the affair with Tomalin that ended Frayn’s first marriage in 1989. The only insight Frayn shares into that side of his life is when I ask him whether he has any regrets. “Not in my professional life, no…”