Beaver Country wasn’t a fancy school or hard to get into. It was small and relaxed and it had a huge range of kids, a lot of kids on bursaries. It wasn’t stuffed full of geniuses but you had room to achieve. It had the most wonderful English teachers, including Miss Kelly O’Connell. We did lots of Shakespeare together and I loved the long speeches. I particularly remember Henry IV part I, Hamlet and Macbeth.

Miss O’Connell encouraged writing. She set lots of writing projects and she was wonderful at teaching it. There are things I still remember her saying when I write, such as avoiding the passive. She was very unglamorous, not sophisticated, but she had a wicked sense of humour and seemed to love teaching us.

At that time it was traditional in the US to invite your favourite teacher to lunch at some point in the school year, and I invited Miss O’Connell. It was terrifying. We ate in the dining room and we were all on our best behaviour, and I remember being amazed to see my teacher chatting to my mother in an apparently natural way.

My parents were academic - my father taught surgery at Harvard and my mother was a social worker - and there were lots of books at home. I was born loving books and reading. I adored A Little Princess and The Secret Garden and A Wrinkle in Time (by Madeleine l’Engle). Horse books were my main passion. There was a point when I actually ran out of horse books to read.

I went to Harvard at 17 and read English and fine arts. Dimitri Hadzi, who taught me sculpture, was so divine. He was a Greek American and the sexiest man, though he was 5ft 5in, if that, and he looked like a gnome. God knows how he got away with it but we were all besotted with him. All the other professors seemed by comparison so stuffy and full of their own self-importance, and they had been there for a hundred years. Dimitri had lived in Rome and he brought a sense of somewhere else and a sense of intense passion about art. He was caring as well as charismatic and very inspiring and encouraging.

He said I should go to art school, and it was because of him that I went to St Martin’s in London for a year to do sculpture. I lived in Camden Town and I loved it, but it seemed so grey. Everything was on strike, there was a bread strike - I had never heard of such a thing - there were power cuts all the time. I first became aware then that there really had been a war here, that the Channel Islands had been occupied, that it had been very close. If you grow up in the US war is always “over there”. That stayed in my head until I came to write How I Live Now, about an English family and their American cousin caught up in a war in England.

I worked as an advertising copywriter until my US deal for How I Live Now came through. I wasn’t good at it: it’s so hard to quantify what will work in advertising. I wanted to try writing a novel - I knew that technically I could write but I didn’t think I could do plot - so I took a leave of absence from work for two months. I wrote a pony story because there are only about two plots for those. I won’t publish it but it helped me get an agent, Catherine Clark. If she hadn’t been my agent, I would have carried on writing pony books. I told her I was thinking about a book for young adults and she said: “Just write the very best book you can write.”

I had the beginning and end of How I Live Now in my head then, and I said I would come back to her in six months. I worked like a demon writing after work every night, and finished it in three months. I thought, “This writing game is easy”, but my second novel, Just in Case, took a lot longer.

Writing fiction was always my fantasy when I was young but I was too self-critical and for years, if I read something wonderful, instead of inspiring me it would put me off even trying.

Copywriting has helped me: you realise that writing is a craft, that you can get better at it and that you have to edit and take criticism. You learn to get your narrative arc in place because you only have 30 seconds to tell your story.

Author Meg Rosoff was talking to Geraldine Brennan

The story so far

1956 Born in Boston, Massachusetts

1961-67 AE Ainger elementary school, Waban, Massachusetts

1971-74 Beaver Country day school, Brookline, Massachusetts

1974-79 Reads English and fine arts at Harvard University with a year at St Martin’s College of Art in London

1979-88 Works in publishing, public relations and on the 1988 Democrat presidential election campaign

1989 Returns to the UK and starts a career as an advertising copywriter

2004 How I Live Now published by Penguin, wins Guardian Children’s Fiction Prize

2005 How I Live Now wins Branford Boase Award and Michael J Prinz Award, and shortlisted for Orange Prize for new authors and Booktrust Teenage Prize. Meet Wild Boars, a picture book, published

2006 second novel Just in Case published