While I was writing the book, one of my children was diagnosed with dyslexia. Dyslexia is a very tiny word for a wide-ranging neurological condition that affects different people in different ways. But I was reading an awful lot about it, to try and find ways of helping my child. I think a lot of fiction comes from this desire to confront unanswerable questions, and it's heartbreaking to see your child, a bright child, struggling so much with something that others are finding so easy. It's such an assault to the child's self-esteem and, as a mother, it's hard to watch.

It is a terrible thing to want something you cannot have. It takes you over. I couldn't think straight because of it. There was no one else, I realized, whom I could possibly tell.

Always, at the end of every book, there are things you will be unsatisfied with, and still more things that later on you will realize were not right. But mistakes are part of what a book is. That itchy, dissatisfied feeling at the end of a novel is useful. It's what keeps you writing and gets you writing the next one. It's what keeps you learning.

I think it was Rose Macaulay who said, "A house unkept cannot be so distressing as a life unlived."

You need a lot of energy to get a novel finished. You need an ability to ignore everyone around you. It's why I don't read my reviews any more. I know a lot of people say that, but I really don't read them.

She wanted to say, no. She wanted to say, I have a son, there is a child, this cannot happen. Because you know that no one will ever love them like you do. You know that no one will look after them like you do. You know that it's an impossibility, it's unthinkable that you could be taken away, that you will have to leave them behind.

All the time I was plowing through books on dyslexia, I found myself asking: what if, what if? What if you were a kid the 1950s with this condition, when there were no books on it, when there was no understanding of it. I remember kids in my class at school who just didn't seem to progress in their reading. There was no extra help. People just thought, "Oh, he or she isn't so bright, or they're obstinate."