So it's a surprise when without the slightest of prompts he announces, "I wrote for the Yorkshire Post once" and then proceeds to wax lyrical about his time in Yorkshire as a child.

He also throws in several other unrelated topics, from his childhood in India, to his thoughts on 20/20 cricket.

It is all gratefully received. Facing a playwright who gave his name to the term Stoppardian – meaning a piece of writing in which the author uses witty wordplay to create comedy while addressing philosophical concepts – it is easy to feel intimidated.

It is something that Sir Tom has become used to, but while he recognises his reputation so often precedes him and his mere presence makes many a nervous wreck, it is with regret.

He experienced it most recently and keenly when in rehearsals for Hapgood, his 1988 play which is being revived in a co-production between the West Yorkshire Playhouse in Leeds and Birmingham Rep. Directed by the highly praised Rachel Kavanaugh, Stoppard was invited into rehearsals on occasion.

"I am the least intimidating person in my own heart, but whenever I went into rehearsals, I kept being told that the actors were nervous because I was sitting there. I deal with it by just trying to dissolve away any sense of even being there, but..." Stoppard's voice trails off, leaving a sense of sadness in the air, before justifying his presence in rehearsals.

"It helps for the practicalities of translating what's on the page on to the stage. Often there are little misunderstandings."

Those "little misunderstandings" are inevitable when you have a writer whose intelligence and expanse of reading seeps through the lines of his plays. He is the creator of brilliant plays like Rosencrantz and Guildenstern are Dead and the Oscar-winning screenplay Shakespeare in Love, so it is unexpected to find a man who seems to just want to have a normal chat. Some would say that Stoppard is simply being made to lie in the bed he made – you can't create dazzling brilliance and expect people to be satisfied passing the time of day discussing the weather.

But Sir Tom seems to crave normality, which is perhaps why he seems so keen to reminisce about his time on the Yorkshire Post, a time before fame hit.

"I knew an editor of the paper Bill Oliver (deputy editor of the Yorkshire Post in the Fifties and Sixties) – I knew his son who was an artist. I'm not sure how it came about, but I was in Pamplona sometime around 1960 and he asked me to write a piece about the festival, with the running of the bulls," says Stoppard.

Of course, Stoppard wants to talk about the Yorkshire Post: newspapers and the county are in his blood. He began his illustrious career as a local journalist on the Western Daily Press in Bristol, but before that had been educated at Pocklington School.

Stoppard ended up in Yorkshire following an itinerant childhood which saw him born in what was then Czechoslovakia, before fleeing to Singapore with other Jews when the Nazis invaded. The family was evacuated to Darjeeling to escape the Japanese invasion of Singapore, although his father remained behind as a British army volunteer and died in a Japanese prison camp after capture.

His education as a young boy in India ended when his mother married a British army major named Kenneth Stoppard, who gave Sir Tom his English surname and moved the family with him to England after the war, in 1946.

"My stepfather came from Chesterfield and one of my first homes in England was in Dore, near Sheffield," he says. "Sheffield was the city where I really grew up, where I would go when I went to the pictures. I still have friends in Yorkshire and I love to visit the Moors.

"Every time I find myself in the proper English countryside, I think, 'What am I doing living in London?' Something deep inside me connects to the English countryside and to Yorkshire. I used to go on fishing holidays on the river Nidd."

Sir Tom gives the impression he would be happy to continue in the same vein for hours, but we should, however, talk about Hapgood, which opened at West Yorkshire Playhouse last night. Starring Josie Lawrence, it is about a female spymaster who attempts to trap a double-agent and finds her daughter kidnapped.

"The character is this funny combination of a hard-nosed spymaster and someone with a very strong maternal instinct," says Stoppard. "Josie is doing a fantastic job of the character, she's wonderful."

What Stoppard forgets to mention is that, as well as being a spy thriller, it also takes in quantum mechanics and attempts to explain some of the ideas behind the theory. Not for the first time the writer find himself almost apologising for his intellect.

"Yes, there is an exploration of quantum mechanics and the idea that by observing something you change its state – but don't forget, this was written at time when books about Schrödinger's Cat were minor bestsellers," he insists.

"The truth is, the play sounds much more complicated than it is. I did return to it 10 years later and took out some of the things that were just the author enjoying himself, some things the audience perhaps didn't need to know."

He is being self-effacing. and once again keen to throw off the unwanted mantle of impenetrable intellectual. "I'm 70 for God's sake," he laughs, when asked about the sorts of subjects he would like to tackle, and returns to an old passion. "I love cricket, but I'm not even that knowledgeable about the game any more. With the 20/20 league coming along, I just find it slightly depressing.

"I remember going to watch the three-day county matches at Yorkshire which I much enjoyed. You used to be able to drive up to a county match, to the boundary, and sit on the car bonnet eating a picnic. It's all changed now, the game's become a money cow."

And the reminiscences begin again.

Hapgood is at West Yorkshire Playhouse, Leeds to May 24.