In his 2007 autobiography – a book with a distinct emphasis on the auto – British racing driver Jackie Stewart begins one chapter with a breathtaking line: “Imagine an eleven-year window of time when you lose fifty-seven – repeat fifty-seven – friends and colleagues, often watching them die in horrific circumstances doing exactly what you do, weekend after weekend”. In the 1960s and 70s, the era during which he won 27 Grand Prix titles and was Formula One’s world champion three times, racing was a barbaric sport.

Jackie Stewart laments loss of German F1 Grand Prix

Once, in 1966, as he drove out of the pits in a Ferrari 250 LM during the Grand Prix Ile de France, he glanced to his left and saw two dead bodies, “shattered beyond recognition” a few metres away. It was, he writes, like a scene from a medieval battlefield. And still the race continued. Fatalities pile up, as swiftly relentless as the grimmer sort of soap opera: youthful actors enter; briefly, brilliantly, shine; are smashed, or burnt, to death. (Early on in the 547 pages, I made a note that the bloody jostling resembled Game of Thrones, before realising Stewart had, literally, been with House Tyrrell [sic]. Ken Tyrrell had founded the Tyrrell Racing Organisation in 1960 and effectively launched Stewart’s career.)

Throughout the carnage and funerals, Stewart compart­mentalised his emotions. When he passed those mangled corpses, for example, he pressed on the accelerator and did a record-breaking lap. Off the track, however, he searched for the best doctor he could find to be his personal standby physician each time he raced. (In case you snort – as officials did – at such apparent preciousness, bear in mind that, at the time, the chief medical officer in charge of one circuit was a gynaecologist.) He compiled a list of leading surgeons in every country where he raced. He conducted track inspections.

His life reads as a strange mixture of derring-do and caution. In this, he resembles his mother, who was passionate about driving. His parents owned a garage outside Glasgow, Scotland, and Mrs Stewart loved to try out every car that came through their dealership. But she absolutely forbade her younger son to drive professionally; his brother, Jimmy, eight years older and a well-known racing driver in the 50s, had retired at the age of 24 because of the stress it had caused their mother.

When Jackie began racing, therefore, it was under the name A.N. Other. Eventually, his mother found out. There’s a remarkable scene in his book where he visits her to explain. His mother simply looks out of the window and says, “Do you think it might rain today?” Not once in his subsequent stellar career did she ever refer to his chosen profession; when Formula One racing started being televised, his father had to watch his son’s progress at neighbours’ houses.

Jackie Stewart speaks to the South China Morning Post in 2006

The secret of A.N. Other’s identity had been accidentally revealed by a local paper when Stewart married Helen McGregor, in 1962. They’d met when he was 18 and she was 16; Pat Boone’s Love Letters in the Sand was playing on the café’s juke box. She wasn’t marrying an international celebrity, just a mechanic who raced under a pseudonym. Throughout the book, she’s a constant presence, his time-keeper, his pit-lane girl. In 1973, when he retired from racing, she said to him, “Now we can grow old together.”

In July, Sir Jackie Stewart – as he’s been since 2001 – told the British media that Lady Helen, 75, has dementia. He has set up a charity called Race Against Dementia ( to fund research into finding a cure.

“It’s the biggest thing I’ve ever taken on and the most challenging,” he told the BBC. “God gave me a gift – that was easy in comparison with what I’m challenged with here.”

It’s a decade since he wrote his book about fast deaths; now he has to deal with a slow one.

WE MEET AT The Peninsula, in Tsim Sha Tsui. The tele­vision in his Peacock suite is set to a channel bearing his photo and the words Sir Jackie Stewart OBE. He’s just been at the Grand Prix in Singapore and within a few days he’ll be heading to the Grand Prix in Kuala Lumpur but Hong Kong is a stop-off solely to promote his charity. (Neither of us even mentions Hong Kong’s unexpected swerve into Formula E.)

Michael Kadoorie, racing enthusiast and chairman of Hongkong and Shanghai Hotels, which owns The Peninsula, has provided his accommodation. Stewart’s media interviews have kindly been arranged by Rolex, for whom he’s been a global ambassador since 1968. Two representatives from the company are present along with Stewart’s personal assistant, a pukka ex-army chap called Ed, and we’re later joined by Rolex’s managing director here, Daniel Neidhart.

“[American golfer] Arnold Palmer and I signed with Rolex that same year, 48 years ago,” Stewart says, still Scottish of accent, although 1968 also happened to be the year he left Scotland for tax exile in Switzerland. “That’s unusual to say the least.”

He’s a little perturbed that I’m not wearing any sort of a watch. Stewart is particular about such matters (his bespoke shirts have a slightly wider left-sleeve cuff so that his watch can move freely and visibly) and I suspect he views watchlessness as faintly unprofessional. But I know he never wore one while he was actually racing – in an accident, they could “deglove” drivers, flaying the skin off their hands – so I’m not too chastened, and we agree that the people from Rolex can be our timekeepers.

Dementia, of course, is a zone where time ceases to have meaning. One of the diagnostic tests for dementia is a draw­ing of a blank clock face on which the subject is asked to fill in the missing figures. Years ago, I saw my father’s results: a few numbers wandering hesitantly beyond the circle. Was it like that for Helen?

“No,” replies Stewart. “I don’t think she did that one. It was more repeat-after-me, who’s the president of the United States, who’s the queen ... Helen was put through an extra scan because one of those tests showed up a trend that wasn’t there before.”

The initial tests were performed two years ago, at the Mayo Clinic in Rochester, Minnesota, where the Stewarts have been having annual check-ups since 1979.

“I’ve taken more than 700 people to the Mayo,” he says. “They are remarkable.” (Fifteen pages of his autobiography are devoted to its earlier excellence in their lives.)

“After Helen’s diagnosis, I was forgetting things, so I said, ‘I’m off to the Mayo,’” he continues, with no prompting. He’s been famous for so long that he tends to hold forth until interrupted. “I thought I’d better look out and I’d rather know if it’s going to be the case. It came out that I haven’t got dementia. It was a relief but I still couldn’t answer all those questions. I heard about someone the other day who’s got it at 29 years of age, and someone of 46. I think it’s been around for a long time and people were saying – for whatever reason – it’s not important, it’s not a cancer, you’ve still got your physical health. That’s no longer true for Helen. Her mobility is absolutely changed, she can’t go up and down stairs like she used to.”

The family returned to Britain in 1996, when he set up the Stewart Grand Prix racing team with Paul, the elder of his two sons. (In 1999, it was bought by Ford Motor, which renamed it Jaguar Racing.) He and Helen now live in Buckinghamshire, in south central England. His immediate response to her diagnosis was speedy practicality. As you might guess, he’s a floor-the-accelerator kind of man; he’s also so used to being asked questions about himself that he hasn’t completely adapted to including Helen in the answers.

“I’ve put an elevator in the house,” he says. (Years of commentating for American sports channels have left linguistic markers.) “I can afford to do that because I was a racing driver. That’s one of the privileges I have – 99 per cent of people who have dementia don’t have the wherewithal to do that. There are two full-time carers living in and I’ve done a further extension on the house for them, with their own living room and laundry, because as the years go on, I might have the same difficulty, and if I have the best accommodation I might get the better carers.”

He’s also had the kitchen, the living-room and the bed­room adapted. Helen’s bathroom has been re-done with non-slip floors and taps that automatically switch off if they’re left running.

“And by the way, I got my bathroom done at the same time. I thought, ‘Hello, Jackie’s going in the same direction.’”

So I wonder about Helen, gradually disappearing within the refurbished walls around her. They’ve been married for 54 years. One of the many devastations of dementia is that, eventually, both partners end up feeling they’ve married A.N. Other. (“I’ve lost him,” my mother would say of the bewildered man she’d married more than four decades earlier.)

“Oh, she knows me,” Stewart says when I ask. “She misses me, being away. I call her twice a day and she says she doesn’t know where I am, her consumption of infor­mation is not good.”

Her long-term memory, however, is still intact.

“Over the years, she did a whole lot of albums for me, beautifully done with photos, news cuttings, menus signed by Fangio, Graham Hill, Jim Clark ... if we open them out, she’ll tell you everything, like a laser beam. Yes, her speech is fine. She’s still eloquent.”

Which would indicate that Helen has barely com­pleted the first lap in her spiral of diminishment. Every case is different but even when you think you know what’s in store, witnessing the unravelling of a loved one’s mind is a more painful, lengthy process than can ever be imagined. The Stewarts, like other families, can only find that out themselves.

When I ask Stewart his thoughts about the swift deaths he witnessed in his youth versus this protracted one, he says, “I’ve been surrounded by death, I’m not frightened of dying at all. For me to slip away quietly at a certain age would be my desire. I wouldn’t like to be invalided or institution­alised or a burden.”

It’s a shame he left Switzerland then, I say – the 21st-century geographic euphemism for choosing a quick exit – and he replies, with eventual understanding, “I’ve still got a home in Switzerland”.

But he needs (he rubs his face vigorously) to get, as it were, back on track and talk about his charity.

“If I don’t raise money, I cannot provide for the next genius who’s going to find a cure for dementia. I’ve got an appeal: look at the website, it’s where you can give money. And in most countries it’s tax deductible. I’ve put in a million pounds. I need money.”

Yet there are plenty of other dementia charities out there. Why did he need to set up his own? And isn’t Big Pharma already spending billions on research and development for this holy grail?

“That’s on the corrective side,” he says, referring to medication that currently attempts to control dementia. “The big thing I’ve got to do is stop the next generation having it. If a child is born now, there’s a one-in-three chance he’s going to have dementia. I had breakfast with Lawrence Lauder in New York a few months ago. Is it Lawrence, Ed?” (It was Leonard, son of Estée.)

“They wanted me to join with them,” Stewart continues. In May, two months before his own announcement, the Lauder Foundation and the Samuel I. Newhouse [of the publishing family] Foundation announced the formation of the Treat FTD Fund. FTD stands for “frontotemporal degeneration”, the form of dementia Helen has. The foundations jointly put an initial US$10 million into the fund to help with research and accelerate clinical trials.

The Lauders are already well-known, and highly experienced, fund-raisers for research into breast cancer. Why not go in with them?

“For 25 years they haven’t succeeded!” Stewart cries. “No disrespect to him. I’ve got to start a new way of doing it.”

Perhaps this is the moment to mention that his autobiography is called Winning Is Not Enough; his publishers had wanted to call it Driven but Stewart (rather proving their point) insisted otherwise. Success, he says, is about “winning with care and integrity”. And, you get the strong impression, on his own terms.

On his (initialled) shirt, he’s wearing a badge. It’s the logo for the charity, and was designed by WPP, one of the world’s largest advertising and PR companies. WPP’s chief executive, Martin Sorrell, is a Race Against Dementia trustee; his first job, in the late 1960s, was as Stewart’s assistant. The logo shows a fractured capital-letter “D” and before he explains, I was wondering if it was something to do with a dyslexia charity: Stewart makes frequent reference to the humiliation, and subsequent triumph, that being dyslexic has caused him in life.

That child who couldn’t go beyond the letter “p” in the alphabet or learn the national anthem grew up to become intimate with the royal family. His autobiography, dictated over 16 months, begins with a foreword by Princess Anne, the queen’s daughter; and Helen is godmother to Zara Phillips, the queen’s granddaughter. Such connections are a source of great joy. (“You can’t write this,” he instructs me, as prelude to an eyewitness account of the queen’s incisive mind at 90. Aware of Rolex-time ticking on, I suggest we only talk about what I can actually use; but he tells his story anyway.)

You can understand, therefore, why he still believes anything is possible. Nobody knew about dyslexia when he was at primary school, 70 years ago; future generations will be appalled at how little we know about dementia today.

“I’ve got a slightly better chance than other people,” he says. “When you’re successful, if you’ve really got it together, you can carry a challenge like this forward.”

AS A SOP TO READERS expecting rather more on the motoring front from this interview, I ask Stewart what he thinks of Jeremy Clarkson, the former lead presenter on the BBC’s Top Gear programme.

“I know him, obviously,” he says. “He’s been a naughty boy for quite some time. But he’s a nice naughty boy, a clever naughty boy and an amusing naughty boy. If he weren’t like he was, he wouldn’t be so global.”

After a short consultation with Ed about whether or not he should wear a tie, we proceed in a posse up Nathan Road. At the back of The Peninsula Arcade, there’s some new scaffolding.

“That wasn’t there yesterday,” Stewart says, still a man who checks out every detail of his route.

Not for the first time, I think how terrifying a city Hong Kong must be for those with early-stage dementia. The land­scape shifts so constantly it never feels reliably solid. I’ve seen older people standing, hesitantly, on the crowded pavements of Kennedy Town, and I recognise their fearful pause.

A local man I know has a wife with advanced dementia; a few times I’ve met them struggling home together, locked in joint agitation. Their flat can’t measure more than 400 square feet, it hasn’t been specially refurbished and there are no paid carers. Any drug discovery will be too late for her, as it will be for Helen. Something could be done to ease the current suffering, but the government – like Mrs Stewart – is gazing out the window, pretending reality’s unpleasant facts don’t exist. Who will take up the slack?

All the way up Nathan Road, furtive men suggest to Rolex’s managing director that he might like to buy a copy watch. Neidhart accepts these offers of fake time with a good-natured, philosophical shrug. Opposite Chungking Mansions, a man presses a tailor’s name card into Stewart’s nonplussed hand. Nobody recognises him – to the touts he’s just A.N. Other.

When the crossing’s lights change, he steps carefully into the street, checking for traffic, as the heedless, unknown faces swarm past.