Any author of young adult fiction has been asked this question.
The questioners don't mean to offend. To them it's a valid enquiry based on assumptions they've picked up. I can't really blame them - the negative messages are everywhere.
Books written for young people are not very good, we're told. Especially those targeting a female audience. Bella and Katniss - how ridiculous. Sparkly vampires - what a joke.
I suppose you can see their point. If young adult books were valuable, surely they'd be reviewed in the broadsheets. Or covered by BBC Radio Four. Young adult books are not even - oh, the indignity - included in Richard and Judy's book club.
Based on all this evidence, many have come to view young adult fiction as a writer's training ground. Start there. And some day you'll grow up and write a real novel.
The most ironic thing about this mindset is that it diminishes one of the most interesting and innovative genres in fiction today. There is so much happening in the young adult genre - so much good writing and innovation. So much bravery.
I think it's a scandal that the mainstream media continues to ignore and denigrate this massively popular movement because of what is, when you get right down to it, snobbery.
As the writer SF Said puts it: 'Children's literature is just literature, and great children's books are just great books.'
And those great books are selling like hotcakes.
According to industry publication The Bookseller, in 2014, books for young people 'hit an all-time high in revenue and market share, and exceeded sales of adult fiction,' pumping £336 million into UK publishing. It's the fastest growing section of the UK fiction market: In 2014, the market for children's and young adult books grew by 9%, while sales of adult books declined by 5%. In 2014, £1 in every £4 spent on print books was spent on a children's or young adult book.
That's a valuable piece of publishing real estate the media are insulting and ignoring.
For me there is some irony in the fact that I find myself defending this genre now. I did not set out to write young adult books. I came up with an idea for a book series about a secret society not unlike The Bullingdon Club, at an elite boarding school not unlike Eton, and I wanted to write that book.
For me, and for most writers in my genre, the attraction of young adult fiction is the chances we are allowed to take. This genre is not - thus far - limited by convention. We are not constrained by rules, because we are making up the rules as we go along.
This is a brave new world in which writers are allowed to take risks, even to genre jump. My first book was a political thriller. My new book, The Secret Fire, is a fantasy about alchemists in the modern world. My next book will be something else entirely.
One thing they all have in common is that they are written with adult readers in mind. Because here's the thing media are forgetting when they ignore this genre: most readers of young adult fiction are adults.
True young adult fiction is intended, as the name implies, to be read both by adults and those in their late teens. I do not make allowances for my young readers in my writing, and neither do most authors. The storylines are definitely not childish.
The first time I read The Hunger Games, I thought, 'This is not a children's book. It's too violent. Too frightening.' But we forget what we read when we were young. How extreme our tolerance was for darkness.
It has ever been thus. When you stop and think about it, Romeo and Juliette is the tale of two teenagers having unprotected sex and then killing themselves.
We force teenagers to read that.
It's funny, when I first set out to write Night School, I didn't realise that the age of my protagonist meant my books would end up ghettoised at the back of every bookshop under the condemning sign: 'CHILDREN'.
I didn't know newspapers would decline to review it because 'children don't read newspapers'.
Eighteen months after I first put pen to paper, having written 100,000 words, and with my book being translated into 20 languages, I found myself standing in front of 150 teenagers in baggy blue school uniforms, giving a talk designed to inspire them to read.
One of the first questions they asked? 'Do you think you'll ever write a real book?'
The Secret Fire the new novel by CJ Daugherty is out now at all good bookshops.