I still find it strange telling people I’m a writer. I feel a bit of an impostor - for years, I had just been someone with a strange little hobby.

I was writing for about 20 years before I got a publisher. I had written five complete novels and had rejections from 33 agents. I learnt that you didn’t talk to people about writing because they would just think “Failure! Failure!” when nothing happened.

But I didn’t think about giving up. The thing is, I like writing. I had ideas whizzing through my mind and I didn’t want to leave them there.

So I would complete a novel and start sending it out. But by that point my mind would be on the next novel. When a rejection letter comes back, you just think “ugh” and keep going.

I teach violin, piano and group theory classes at Blue Coat, a preparatory school in Birmingham.

I also used to do a lot of teaching in the evenings to get by.

It was very difficult to fit in writing: I was lucky if I found maybe one afternoon a week to write. It took me five years to complete my fifth novel, Astonishing Splashes of Colour.

When I sent that novel out, a small local publisher called Tindal Street Press said yes. They said they would publish about 2,000 copies and gave me a #163;2,000 advance. It seemed very generous at the time. I bought a new carpet with it.

But I didn’t think anyone would notice the book. I just thought maybe the parents at school would buy it. That’s about 200 sales. I imagined by the time I got round to my next novel, interest might have grown.

I was at my mother’s house in Devon when my daughter called me. She had been pottering around on the internet and found that I was on the longlist for the Man Booker prize. My mother didn’t have internet access, so we went over the road to a neighbour who did. I was there, with authors such as Martin Amis. I spent the whole night wide awake, thinking: “I cannot believe it. This can’t be true. How extraordinary.”

Then I was waiting for the shortlist to come out. I just thought: “Is somebody going to tell me if I have made it? How will I know?” I wasn’t sure how it worked.

I was actually at school, teaching piano to an eight-year-old boy called Angus when Tindal Street called and said: “Congratulations, Clare. You’re on the shortlist.” I think they were as astonished as I was. Angus congratulated me, too.

I was high as a kite. It was all so unexpected. I didn’t have anything to wear to the dinner: I had never been to anything like that. I never thought I would win - it didn’t cross my mind. But, at the dinner, my publishers were shocked when I didn’t win, which surprised me.

I had five offers from publishers for my next novel. It was surreal.

I didn’t give up teaching. Teaching is steady. The book world is very unsteady. These things come in dips: you don’t maintain those levels of sales unless you are someone like John Grisham.

I tend not to talk about my books with colleagues. I don’t want to ask if they like them because they may not. I don’t want to embarrass people.

Success meant I could reduce my teaching hours. I teach from midday to 6pm now, which means I can get some writing done most mornings.

Before, I would sometimes fall asleep on my only afternoon off. Now I’m not so tired. It means I can enjoy the teaching more, too.

l Clare Morrall was talking to Adi Bloom. Her latest novel, ‘The Man Who Disappeared,’ is published by Sceptre. Do you have an experience to share? Email features@tes.co.uk.