“One of my standout memories of a night centred around food is from 1987, when Bartle Bogle Hegarty (BBH) was five years old. We hosted a big dinner at the Royal Academy in London and gave everybody a bottle of 1982 Château Meyney – one of the all-time-great years for that vintage and the year the agency was founded. Our guests were taken around the galleries by the curator. It was one of those fantastic evenings where we were all brought together by dinner, by food. I remember we had lamb because bbh has always been the black sheep; it’s a similar animal to the one on Hegarty wine.

I’m not keen on eating in places where the food takes on more importance than the conviviality of the occasion. For me food should support an evening, not be the evening. I’ve eaten at El Bulli and it was amazing but I’d only do it once. I find putting food on a pedestal rather boring. I remember saying to [London restaurateur] Jeremy King, ‘I love your concept of what a restaurant is because the cooking’s good but it’s not trying to overtake the evening.’ I think that’s quite a continental approach to food: the idea is to get people together, to talk and exchange ideas. If everybody feels that they have to sit in silence or talk about the sauces and what went into them, the meal can become a bit of a drag.

My childhood memories of food aren’t stunning, although they are comforting – meat and potatoes, what’s wrong with that? We’ve got potatoes on the table tonight and they’re ordinary but wonderful. Postwar Britain was poor and trying to get back on its feet. It was a country that had been damaged and somehow forgotten its agriculture. France had been defeated but it was still an agricultural country and they went on celebrating food. I think that in Europe a postman can pretty much enjoy what a duke enjoys.

The link between food and drink and advertising isn’t always obvious but New World wine became a good communicator. They couldn’t call their wine “American chablis” so they had to call it chardonnay; putting the grape varieties on allowed people to say, ‘Oh, that’s chardonnay, I’ll buy it again.’

It’s cool to have your name on your wine and I shouldn’t be dismissive of that. But deep down I’m quite shy. I’ve never sought to put my name on things but sometimes you have to. When we started Bartle Bogle Hegarty we were trading on our reputations so our names had to go above the door. Calling my wine Hegarty was simple. If I’d called it Domaine de Chamans nobody would have remembered it. The first rule of marketing: you have to remember the name.

In terms of the advertising industry, I’m afraid my experience is that an idea doesn’t get better over lunch; it gets watered down – or something’d down. An idea is a precious thing. It’s like a baby: you can’t listen to everyone’s advice on how to bring it up. Having said that, work lunches always supported the sort of freewheeling conversations that ideas would appear from and that was always fun.

In a way that lunch culture has disappeared from our industry, which is a shame because you’d occasionally come back from lunch with something wonderful. The accidental nature of creativity is being eliminated. Research is overrated. There is no evidence to suggest that a brainstorming session has produced anything great. I think that allowing freedom and conversation is how ideas emerge. It’s food and drink again.

I make lunches simple when I’m out for work and I’ve never been into big lunches to try and win over clients. I’d much rather celebrate afterwards. Day to day, dinner’s the thing. It’s all about coming home to Philippa, wondering what we’re going to eat, having a glass of wine and talking about our days. It’s a celebration no matter what you’re eating and it ends the day in a lovely way. You might have noticed that I’m trying to eat my fish slowly; I want to keep my ‘last meal’ going. Now pass the potatoes, will you?”

Sir John Hegarty has spent more than 50 years attaining sage-like status in the advertising world. He worked for Charles Saatchi – of whom he says, “Charles had the ego to want a great company with his name on it but not the sort of ego that would stop him from hiring people better than he was” – and in 1982 helped found Bartle Bogle Hegarty. His latest project, start-up incubator The Garage Soho, was set up in 2014. His most well-known works come courtesy of BBH: Audi (“Vorspung Durch Technik”) Johnnie Walker (“Keep Walking”) and Levi’s (he had Nick Kamen strip to his boxers in a launderette to the sound of Marvin Gaye’s “Heard It Through the Grapevine”. The song clearly made an impression on Hegarty).

Hegarty has owned and run a vineyard near Carcassonne for 15 years, producing about 60,000 bottles per vintage; his wine is sold internationally. Hegarty lives in London and France with his partner Philippa, the wonderful cook of his “last meal”.