When I was 17, I read a quote that went something like: “If you live each day as if it was your last, someday you'll most certainly be right.” It made an impression on me, and since then, for the past 33 years, I have looked in the mirror every morning and asked myself: “If today were the last day of my life, would I want to do what I am about to do today?” And whenever the answer has been “No” for too many days in a row, I know I need to change something.

Usually, my irrational bargaining goes something like this: I start working at around 10 if I’m feeling motivated, 11 if I’m not. I reread the work from the day before and/or passages that I think I got right in order to try to set the tone. I write a sentence. I read it aloud. I delete the sentence. I look at the clock and wonder if it’s too early to think about lunch. I tell myself that, if I can make it to 300 words, I can break for lunch.

I love swimming and I'll still be found in the pool, but now I'll be able to do without the 04:30 alarm!

No sir. I'm rather dismayed how many days I have to work on my willpower very strongly in order to get out of bed before 8 o'clock.…I write letters, I write manuscripts, in addition to the book that is in press I have two manuscripts that are going to be published some time this or next year, and I have a whole list of manuscripts that I would like to write.

These days I can usually calm that particular critic down by feeding her a biscuit and giving her a break, although in the early days I sometimes had to take a week off before she’d take a more kindly view of the work in progress.

I couldn’t have asked for better collaborators on the stage play than John Tiffany (director) and Jack Thorne (writer).

I can remember feeling elated after writing the first Quidditch match, which flowed out of the pen and was barely revised afterwards.

As the screenwriter, the majority of my input comes at an earlier stage.

The friends with whom I sat on graduation day have been my friends for life. They are my children’s godparents, the people to whom I’ve been able to turn in times of trouble, people who have been kind enough not to sue me when I took their names for Death Eaters.

Even though I have a highly visual imagination, I’ve had to learn just how much can be said onscreen without a word, and David and Steve have taught me that.