My granddad opened a restaurant in northern Italy in 1963, the year I was born. It was on the shore of this little lake, an hour from Milan, and the whole family worked there. I was the youngest and, from the age of five, my job was to make the fruit salad. I had a little curved knife – I've been good with knives ever since – and I had to fill the biggest container we had. It was light blue, I still remember, and when we had to clean it I would climb inside it. That's how big it was.

I always wanted to be a chef. They were so cool compared to the waiters. My mum thought it was a bad idea, because the chefs were nuts, always drunk. But I didn't want to be an Italian chef. I always thought that if I learned how to cook classic French food, haute cuisine, like Escoffier, it would be for ever. I was 23 when I put on the Savoy jacket for the first time and I thought I'd arrived. After that I went to Paris for three years, because all the old-school chefs in Italy said you were a nobody if you hadn't worked in Paris.

I was so wrong! I hated every single day. The chefs would say: "You're the worst! You're a spaghetti who learned to cook from the fucking rosbif!" I was smoking so much, I don't remember eating a single meal, and I went down to 58kg.

Eventually I went home to Italy and I told my grandmother: "I don't want to cook any more." She was so sweet, she said: "Who wants to be like the French? You are Italian; we are much better. Remember what your grandfather used to say: 'The French, they eat black truffle! We kick black truffle along the ground!'" People talk about technique and science, but what is a restaurant? A restaurant is chairs and tables, but what makes it is the people who work there. They are the blood: the other organs need to be there but what runs around giving it life is the staff.

I love the idea that someone can come to the restaurant pissed off and leave happy. The other night I saw this boy and girl, quite young, walking outside hand in hand. They came in and you could see they were in love, but maybe they didn't realise it yet. I said to the boys in the kitchen: "We've got to really make it magic for them tonight." At 11.30pm, I looked out and he was kissing her, and I thought, "Yeah!" I didn't look how much money we made that day; I didn't care.

That's what gets me up in the morning, and very few businesses are like that. My dentist always says: "I want to be like you." And I tell him: "I never want to be like you! When people think of you they think of lots of pain and a big bill at the end! When people think about me, maybe a big bill at the end, but at least they think about pleasure."

One thing I've learned is that change comes and it comes suddenly. You are never secure in London: it is aggressive and people always want something new. But I'll always love to cook. I say to my wife Plaxy: "Whatever happens, it doesn't matter. We can move to Sicily and have a little bar with a stove and I'll cook three things." While I can still stand, this is what I'm going to do. I can't do anything else.