And children start world-building as soon as they can do anything. They start it very, very young indeed. So they’re exercising this great talent of imagination. They’re becoming humans, actually. They’re growing out of being animals and they’re becoming humans.

And they spend a lot of time doing it and until we send them to school and tell them to actually start learning, they’re doing fine at it. I often wonder what would happen if we just let them carry on doing that. Sort of like they do in Finland, I think, which has the highest educational attainment rate in the world, I believe. In Finland you don’t start to learn to read until you feel like learning to read, which can be seven or eight years old. Anyway, I wouldn’t go on about education, sorry. There’s a lot to get through.

But I do want to keep this idea of imagination in mind that the thing that humans are doing, especially young humans are doing, when they play, is imagining. They’re learning to imagine. They’re learning to think about how other worlds could be.

You think about this world by imagining alternatives to it. And you think, of course, about futures by imagining how the world could turn out. It could be like this. If this happens, it could be like that. This is why we can make bridges and have football teams and design weddings and have parties and have governments and so on and so on – because we can imagine those things.

Now my first point is to say that children learn through play, but adults play through art. So I don’t think we stop playing. I think we just carry on doing it, but we do it through this thing called ‘art’.

And so the reason I made that big list of things – which could, of course, have been endlessly long – was because I want to say that all of those things, from the most exalted (with inverted commas) like symphonies, to the most mundane like cake decoration or nail painting or something like that, they are all doing the same thing. They are all the construction of little worlds of some kind. Okay, so you’re thinking how’s nail decoration a world?