Readers have been getting in contact recently to talk to me about my books. Sometimes they apologise for emailing, as though reading what they have to say doesn’t fill my heart with utter joy. Honestly, knowing that a book I wrote has made a difference to an actual person’s life is the most unexpected and amazing thing about being an author. Please don’t ever stop emailing, and please don’t ever think that you’re going to bother me or waste my time. I love every single email, and I promise to reply to every one.

I had a particularly wonderful email yesterday from Willa, who wanted to tell me that ‘Hazel is like a friend to me’. I completely love this. Like a lot of authors, I had a slightly lonely childhood, and one of the things that made me feel better was spending time in books with my favourite characters. I was (and am still) pretty sure that Mitt and Cassandra Mortmain and Princess Cimorene were real, somewhere – and (confession time) the one Agatha Christie novel that I have never read is Curtain, because I can’t bear the thought of Hercule Poirot dying.

But the other thing I really like about Willa’s comment is that I feel exactly the same way. It’s really hard to talk about without sounding bonkers, but I am definitely one of those authors who believes in their characters. I know lots of authors don’t, and I think that’s perfectly valid, but to make my made-up people live on the page they need to exist absolutely in my head first. It’s a funny sort of double-think: I know that I won’t ever turn around and find Hazel sitting next to me, but when I really consider that fact I’m astonished. She and Daisy feel so real to me – I know what they’d say in any situation and I know the way their minds work. They’ve been the voices in my head for years, and the fact that now they’re in your heads too is incredible.

So, thank you Willa, and thank you to everyone who’s contacted me so far. I’m more and more convinced every time I get a new email in my inbox that I have the smartest and best readers in the world.