My uncle had paranoid schizophrenia and from a young age I was aware of his tangled thoughts and how the way he saw the world was different to everyone else. It terrified me but it also fascinated me. I wanted to understand more about how the mind worked.
I looked up ‘psychiatrist’ in a careers book in the library and it said you had to have a medical degree. I thought, well, that’s that then, and I shut the book. I believed I was no good at science and as far as I was concerned, I never would be.
I didn’t know what else I wanted to do, so I left school when I was 15. I only planned to take a couple of years out, but once you start working, the idea of going back into education slips further and further away.
I started out waiting tables at my mum’s cafe, then I worked as a secretary; a kennel maid at a dog rescue centre; a bartender; a pizza delivery person. One seemingly unimportant job to another for 15 years.
It was difficult to see my school friends do their A-levels, go to university and find careers in law, medicine, dentistry, and teaching. It felt as though they were moving forward while I was standing still.
I still hankered after medicine. I would read medical books and textbooks on neurology just for fun. I would take any opportunity to learn. That’s how I ended up taking a first aid course in the village hall. I told one of the paramedics I would have loved to have done medicine but I felt I was too old now (in my early 30s). The paramedic assured me how wrong I was and, emboldened by his words, the very next day, I applied to do science A-levels at my local sixth form college.
Most of the people in my class were 16 or 17 years old. There was a lot of coursework, which we didn’t have when I was 15, but the course was really fun.
The biggest thing that had changed was my attitude. I went in with an open mind and found that I actually enjoyed science because I believed I could do it.
I applied to Leicester Medical School in 2005 with one glorious O-level in French and my predicted A grades in A-level Biology, Chemistry and Physics.
The professor who interviewed me was fixated on my age. ‘At your age, do you think you can manage the workload?’ he asked. ‘At your age, do you think you can manage travelling each day?’, ‘how will you feel, at your age, if your consultant is younger than you are?’
I told him: ‘if you want to reject me, don’t reject me because of my date of birth.’ He raised his eyebrow and I thought, ‘I’ve blown it now’. But two weeks later, I received an offer.
It was really hard. My friends thought I was out of my mind. For five years I used to get up at 2.30am to walk my dog, then drive for two and a half hours to campus. I would sit in my car and study, then have eight hours of lectures and drive home.
I spent all my student grants on fuel and textbooks. My mum was supporting me because you’re not allowed to work when you’re at medical school. There were days where I had to choose between a packet of crisps and a cup of tea because I couldn’t afford both.
But I got through it feeling lucky to be there because I’d wanted to do this for such a long time. The people were amazing and despite everyone being much younger than me I made incredible friendships.
We saw things that people never see. You go to a dissection room together and you see a dead body and you start dissecting it. That’s a surreal experience that 99 per cent of the population will never have. So it doesn’t matter when you were born, it doesn’t matter how old you are, you’re there with somebody, doing something extraordinary, and that’s what bonds you.
I qualified in 2010, unable to believe I’d actually done it. I got my first job (after being a junior doctor for two years) as a psychiatrist at a hospital in Staffordshire. I loved going to work every day. My weekends were spent looking forward to going to work on Monday – that’s how much I loved my job.
Looking back, I wouldn’t do anything differently. I would still go into medicine at an older age because it made me a better doctor. My mind was more open to learning, and the jobs I did after school taught me an awful lot about people. Working as a doctor in A&E was very similar to working in a takeaway on a Saturday night. There was a lot of vomit and you could smell a fight. A lot of the junior doctors that I trained with were 19 and they’d never experienced that side of life. That gave me an advantage.
I strongly believe that everything happens for a reason. Sometimes you look back on your life and it all just suddenly makes sense. That’s how I feel about my decision to write a novel, The Trouble with Goats and Sheep, which was published in January 2016 and became a Sunday Times bestseller.
There was a lot of publicity to do for it and the publisher wanted another book. I’d worked so hard to be a psychiatrist but then all of a sudden this amazing opportunity came along and I couldn’t do both. So I left my job when my contract ended in September 2016 and I have been writing full-time ever since.
I miss it every day. I miss the patients because they changed me - they taught me about courage, humour, wisdom, tolerance and bravery. They changed the way I look at the world.
As told to Katie Russell
Joanna Cannon will be speaking about her latest novel, A Tidy Ending, at the Telegraph Extra event at Soho Hotel on 26th May