Stewart, 86, was born near Dumbarton in Scotland. After leaving school at 15 he trained as a mechanic at his father’s garage. He raced in Formula 2 and 3, and won the F1 championship in 1969, 1971 and 1973. He won 27 grands prix, later becoming a commentator and founding the Stewart Grand Prix team with his son Paul. He lives in Switzerland with Helen, his wife of more than 60 years, who has frontotemporal dementia. His younger son, Mark, helps him run the charity Race Against Dementia.

I’m not a very early riser these days, although I wake at about 7am and go through a 35-minute exercise regime. Breakfast is papaya and a boiled egg, then I like to walk my Norfolk terriers, Jack and Jill, for an hour or so. They’re my best friends and often sleep beside me.

Our house stands on the banks of Lake Geneva and looks towards Mont Blanc. We’ve lived here since 1968 but also have a place in Buckinghamshire — a lovely old game farm next to the prime minister’s country residence at Chequers.

Helen was diagnosed with dementia in 2014. She’s now 84 and needs 24-hour care. A few years ago I built a specially adapted apartment next to our house where she can be looked after by specialists. I’m fortunate I could afford that — I didn’t want her to go into a home.

A lot of people with this type of dementia eventually go into care homes, and after setting up Race Against Dementia in 2016 I visited a few. Sometimes I came out in tears. It’s a terrible illness and there’s no cure. My charity wants to change that so I’ve invested millions in research.

• Dementia has stolen my wife’s past, says Sir Jackie Stewart

At midday our chef might make me a pasta dish. I may not see Helen until after lunch as she follows a daily care routine. In the afternoon and evening we sit together — the whole point of having her so close.

We met as teenagers on a blind date at Dino’s café in Helensburgh, a seaside town on the Firth of Clyde. We started going out and that was that. I was a mechanic then and Helen knew me as a champion clay pigeon shooter, not a racing driver. I was a member of the Scottish shooting team.

Sport gave me confidence. At school I was treated like a dunce; I had dyslexia but nobody knew about it back then. I won my first shooting competition because it was New Year’s Day — all the other shooters were hungover but I was too young.

• I felt like a dummy until learning I was dyslexic, admits Sir Jackie Stewart

No one taught me to drive but I learnt a lot from my brother, Jimmy. He drove for the Ecurie Ecosse team and raced at the British Grand Prix in 1953. I’d go to Silverstone and Goodwood with him and fill my autograph book with famous names — it was the era of Mike Hawthorn, Stirling Moss and Juan Manuel Fangio. I still have it. My first car in the mid-1950s was an Austin A30 that cost £375. I saved all my tips at the garage to buy it.

In the 1960s motor racing was glamorous and exciting. Helen was often there in the pit lane, operating the stopwatch and encouraging me. The downside was that it was dangerous. I lost so many close friends, including Jim Clark and my team-mate François Cevert. Every weekend we put our lives on the line. The establishment didn’t want change and I would have been more popular if I hadn’t spoken out about safety standards. I had death threats — men even tried to break into the house when Helen was there with the boys.

• Sir Jackie Stewart: I got death threats for making racing safer – it’s my greatest feat

This summer I’ve been at Goodwood to commemorate 75 years of F1 and my unbeaten record time on the track there, which I set jointly with Jim Clark on Easter Monday in 1965. Jim was a two-time world champion and a fellow Scot. He died a few years later in a racing accident at Hockenheim. I held it together at so many funerals but I cried that day.

I still like to watch a grand prix and go when I can. I see no reason why Lewis Hamilton couldn’t find success at Ferrari. Red Bull has reigned supreme for so long, I think the sport and the fans needed to see a change.

I might have a light salad for supper. I’ll take Jack and Jill for another walk. I don’t drive much any more but it’s important to focus on what we can do in life, not what we can’t.
Sir Jackie Stewart is at the Goodwood Revival festival, September 12-14; goodwood.com

Words of wisdom

Best advice I was given
Think carefully about who you hang out with and behave correctly

Advice I’d give
Never compromise on your health and make sure your accounts are in order

What I wish I’d known
Not to get angry — because you can say things that you wish you hadn’t