In the same way, photography, for me, has fragmented. You do have people doing bodies of work - often with found photographs - that are quite hard to understand unless you got a very sophisticated visual history behind you. But there are different camps.

We sort of understand how painkillers work. You take one, and it reduces your headache. We don't understand how photographs work. And that, to me, is an essential problem as a practitioner.

After my mother died, I lived with relatives. Reading was a means of escaping into other worlds, as photography, much later, was to become.

There was a time, right up until the end of the Second World War and beyond, when white people in Europe thought that they basically owned the world and that everybody else was a sort of servant, or a curiosity, or whatever. And that informed 99 percent of the photographic practice that was done. Without being able to address that, I felt I would have failed in my attempt to explain what the urge to document is.

As humans, we need to question all these notions. What does freedom mean for us? What are our responsibilities? It takes one-250th of a second to take a photograph. So I have the whole of the rest of that second - and of that day - to think.

I think, oddly, that the world of the amateur is quite self-contained, and it depends on "likes" from other amateurs to perpetuate itself. Of course an awful lot of my colleagues are involved with Instagram - they get likes and dislikes, maybe just likes, I don't know - but I think that it's far less self-contained, the world I work in. It goes off in different directions, and is dependent on responses different from a tick or a like or whatever.

It's quite difficult to write about photography as a photographer. A lot of better photographers than me have declined to do it.