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."

As other authors have realized, heat can have a strange effect on us, can cause odd chemical reactions in the brain. Heat can bring out secrets; it can change people's personalities.

I think all families have these secrets, and it's sometimes the strangest things that bring them out. That was part of my interest in the heatwave, in heat as a catalyst for uncovering truths. I was reading Alice in Wonderland to one of my kids recently, and I remembered that it starts on a really hot day. Alice falls asleep because of the heat; the whole story is predicated on falling into a heat-fueled dream.

For a while I used to listen to those whispers about babies costing you books, and Cyril Connolly's loathsome quote that "There is no more somber enemy of good art than the pram in the hall." But it's rubbish. Absolute rubbish. A huge amount of your work is done when you're not at your desk. Knotty problems that you need your unconscious to solve. So it can be helpful to walk away and focus on other things and it can be helpful to be a bit harassed in your daily life, to be hungry for time to write.

The key thing in my becoming a writer was going on a Arvon Foundation residential writing course. I took with me a really messy twenty thousand words of something that later became After You'd Gone, my first novel. My tutors were Barbara Trapido and Elspeth Barker.

You learn so much with each book, but it's what you teach yourself by writing your own books and by reading good books written by other people - that's the key. You don't want to worry too much about other people's responses to your work, not during the writing and not after. You just need to read and write, and keep going.

Despite being from Ireland, I've always avoided writing about it, for two reasons. For a very small country, Ireland has produced an astonishing number of literary geniuses, and at some level I probably never felt, having left as a toddler, that I had the right to try and add my voice. That's part of it. But I also didn't want to write something that was the equivalent of the Irish theme pub. You find them all over the world. The idea of producing a novel that might replicate that type of ersatz really set my teeth on edge.