McQueen was born in west London to Grenadian parents, grew up in leafy Ealing and went to a very multicultural school where he was one of the cool kids, on account of being big and good at football. "It was fun, we laughed all day, I didn't do any homework ever, we just laughed." When I ask about his relationship with authority as a child, he replies lightly, "Authority was good, that wasn't a problem. I wasn't a troublemaker, I was good." But then I ask when he has felt most powerless in his life, and his expression darkens. "At school. God, that was horrible."

By the age of 13, one class of academically gifted kids had been creamed off for special attention. Then there was 3C1 class: "For, like, OK, normal kids." And then there was 3C2: "For manual labour, more plumbers and builders, stuff like that." McQueen was put in 3C2. At first, he says mildly, "I don't know why. Maybe I deserved to be," and seems about to drop the subject. Moments later: "That inequality – I fucking loathe it with a passion. It's all bullshit, man. It really upsets me."

When he went back to present some achievement awards 15 years later, the new head admitted to him that the school had been institutionally racist. This did not come as news to McQueen. "It was horrible. It was disgusting, the system, it was absolutely disgusting. It's divisive and it was hurtful. It was awful. School was painful because I just think that loads of people, so many beautiful people, didn't achieve what they could achieve because no one believed in them, or gave them a chance, or invested any time in them. A lot of beautiful boys, talented people, were put by the wayside. School was scary for me because no one cared, and I wasn't good at it because no one cared. At 13 years old, you are marked, you are dead, that's your future." He doesn't want to think about what his future would have held had he not been able to draw. "Not good. Not good."

But his talent for drawing saved him, and when he stayed on to take A-level art, he got to know the kids who had been the school geeks in the higher sets. "And I realized they were just so cool." They would all watch Dennis Potter's The Singing Detective and talk about it, and suddenly McQueen was having conversations he'd never imagined. After a few false starts at local colleges, he applied to Chelsea College of Arts, didn't have the grades, but got in on the strength of his portfolio.

Unsurprisingly, the sociocultural landscape of art school in Chelsea might as well have been another planet to McQueen. But he didn't notice. "No, never. For the first time I was happy. I had an environment I could work in, and so I was happy. I think I'm like Mr Magoo a lot of the time, you know. I just focus – focus on my work. I just wanted to focus on that." After graduating from Chelsea and then Goldsmiths, at the tail end of the YBA scene, when Damien Hirst and Tracey Emin were busy capturing headlines, he moved to Amsterdam. He says he cried when his daughter started school, because "it was just so beautiful, how the school was. It was so different." Private schools don't exist in Amsterdam, and the city's quiet egalitarianism had been part of its appeal. But in the past McQueen has said he chose Amsterdam chiefly because "no one comes here, so I'm never bothered."

It occurred to him recently that he has "hardly any friends", when he looked at his phonebook and realised almost every number was a work contact. "But that's cool. That's good." I'm getting the impression that beyond work and family, the rest of the world doesn't figure much for McQueen. "It does, it does," he says at once, then stops and asks himself, "How does it, Steve?" Struggling to come up with an answer, he stalls. "Well, in what way, for example?"

Well, most people would be able to name at least one thing outside work and family that means the world to them. It could even just be a football team. "Oh well, I gave up football. It affected my day too much. It's just stupid." He used to be a fanatical Tottenham fan, until he decided not to be, and he now no longer gives the club a thought. Is there anything else important in his life? He thinks hard, and comes up with nothing. "Well, my work just takes up a lot. I mean, I don't 'go to work', I don't have a studio, it's just happening all the time, at the kitchen table, hovering, in bed. I wouldn't call it my work. I'd call it my life." It's that fusion that makes his life interesting to anyone who follows his work.

But McQueen seems uncomfortable with self-examination, so I'm surprised when he calls a few days later to say, "I thought we hadn't really finished the conversation last time. An hour and a half isn't long enough to get there – and I want to get there, wherever it is, I don't know." It's true, he agrees, that he doesn't like talking about his childhood. "I tend to not think too much about that. But I thought the school stuff was interesting. It was a very early stage of my life to see the discrimination against Black and working-class people, and I needed more time to think about that. It takes time." Then his voice becomes slightly strained. "I've never said this before, ever. But I was dyslexic. And I've hidden it, because I was so ashamed. I thought it meant I was stupid." He pauses. "Also, I had a lazy eye. So I had a patch. When you're in front of the chalk board, you still can't fucking see. So it was a terrible start. And people make judgments very quick. So you're put to one side very quickly."