Unlike Agatha Christie’s famously long-running play The Mousetrap – 62 not out – the exhibition put on by London’s Bankside Gallery to mark the 125th anniversary of her birth ended before most of us even knew it had begun.

Agatha Christie: Unfinished Portrait featured never-before-seen photos from the author’s private collection displayed with apposite quotations from her work.

The photos moved on to the International Agatha Christie Festival in her native Torquay. They remain on display there (at Torre Abbey) until October 18.

What a pity the show is not touring to Oxfordshire with which, of course, Dame Agatha also had strong links. Married to a fellow of All Souls, the archaeologist Sir Max Mallowan, she lived for a lot of the time at Winterbrook House, in Cholsey.

She was not actively involved in village life (unlike her creation Miss Marple) but she was patron of the am-dram society and a familiar figure in the front row of their performances, in a mink coat and plimsolls in later days.

She died at Winterbrook House in 1975, aged 85. She is buried in the nearby churchyard of St Mary’s.

That she remains (unlike many writers of her generation) a vibrant part of 21st-century cultural life is evident from the popularity of her characters on TV (including the new Tommy and Tuppence dramas) and flourishing sales of her books.

The novelist and biographer AN Wilson paid tribute to her in The Times a month ago in an article headlined: “Ignore the snobs – Christie was a genius.”

I don’t think you would find many snobs eager to ‘diss’ her, for her appeal has always been remarkably broad based. WH Auden was a fan, saying: “For me, as for many others, the reading of detective stories is an addiction like tobacco or alcohol.”

Mercifully, I am in thrall to none of the three, though I have a marked taste for alcohol and for whodunnits – those by Christie especially.

I have read them since I was 10, beginning with – I forget in which order – The Hollow, considered “a truly wonderful novel” by AN Wilson, and an earlier Hercule Poirot adventure, The Murder on the Links.

Poirot, with his prissy neatness and “little grey cells”, seems to me a much better drawn character than Marple, with her “village parallels” and tedious knitting.

I liked 4.50 From Paddington (1957), though, chiefly for its railway setting. I can never hear Borodin’s String Quartet in D without thinking of the film version, Murder She Said (1961), whose theme music appears to borrow its principal theme.

The film starred the wobble-chinned Margaret Rutherford. Asked her opinion of the casting, Christie left it to her secretary to reply: “Mrs Christie has asked me to tell you that, while she thinks Miss Rutherford a fine actress, she bears no resemblance to her own idea of Miss Marple.” Interestingly, however, it was to Rutherford, that next year’s Marple novel, The Mirror Crack’d from Side to Side, was dedicated.

I recall reading this as it came out, in a Collins Crime Club edition, borrowed from the library. I can picture its cover to this day.

Four other covers from these editions, complete with the books that they contain, all Miss Marples, were recently acquired by me. I bought them in excellent condition from a charity shop in Leek, Staffordshire. They are facsimiles, copied from the original books in 2005.

I have so far read two. Though I thought the plot potty, At Bertram’s Hotel (1965) delighted me with its thinly disguised portrait of Brown’s Hotel, in Mayfair, where I have been lucky enough to stay.

“It’s just like stepping back 100 years. It just is old England,” says one of the characters. It still is.

The Body in the Library (1942) is notable for its ready wit, some of it self-referencing.

“It was true,” Christie writes, “that Miss Marple’s nephew, a writer, and therefore erratic, had been known to ring up at most peculiar times.”

Asked at once point if she is a detective story writer, Miss Marple replies: “Oh no, I’m not clever enough for that.”

But of course her creator very famously was.