There really is no difference in the actual writing or plotting. I choose to tell different stories for the younger reader and, of course, I would never put sex and extreme violence in a YA book. But writing for adults and children requires the same care and attention.

When you've lived as long as I have, nothing much surprises you.

The Elders had nothing but contempt for human emotion; they considered it their biggest weakness. Perenelle knew it was humankind's greatest strength.

Research is always the best part. As we dug deeper into the history and mythology behind each of the hallows, we discovered more and more stories - some of them deserving of novels in themselves.

Some writing courses will advise you to write what you know. I've always thought this is very odd advice ... because it means, for example, that I should not be writing about Nicholas Flamel, because I didn't live in France in the 15th Century, I was not an alchemyst, am not immortal (despite the rumours) and do not know magic.

It's always been Apple's goal to ship something we were proud of and something people would be proud to own, and I think that's still true from thirty years ago.

In my experience, we only ever regret the things we have not done.