Everyone has a novel inside them, but when is the best moment to start writing? Tony Schumacher on going from the bottom of the class to becoming an author at 46 Helena Coggan tells Kate Kellaway what it feels like to be published at 15

How did I get here?

I mean, seriously, it is a mystery to me. I keep looking around my office, just stopping for a second and thinking: “How did this happen?”

Not once, no one single time, did it cross my mind that all this was going to happen. Let me explain why. I was thick at school – properly thick. I was so thick that in the first year of primary school they stuck me in with what teachers used to refer to as the “remedial class” or what the kids called the “divvies”. I was a divvy.

I didn’t speak till I was four, and no matter how hard my mum and dad tried, I couldn’t write either. Something just wasn’t working in my head. I was a happy child; I know this because I have vivid memories of being in my cot and laughing like a drain as my brother and sister gave me a toy train for Christmas.

When I got to school (after clinging on to the door knocker every morning and screaming the street down), I’d sit on my own in the corner and ignore the teacher and the other kids, hoping they’d all just go away. At some point in that first year of primary school I learned how to write my name, and that enabled me to bump up a few classes in my second year. The next seven years or so were utterly wasted on me. I hated school. I had friends, good friends who are still friends now, but I knew the education system was utterly wasted on me; it didn’t seem to fit me, so I laboured with it, as if it was a hand-me-down blazer. People hoped I’d grow into it, but I never did. I couldn’t wait to leave. I counted off the years, the months, the days, the hours and then the minutes, and then I left.

Facebook Twitter Pinterest Tony Schumacher Photograph: Murdo MacLeod for the Observer

And then I went back. Sixth form, because my mum and dad literally pleaded with me. Then I left again, after four days, once and for all. I’d had enough. I had two O levels. And one of them was a glorified CSE (geography, if you must know). I think my most stunning failure was that I managed to get a U in my English O level.

A “U”. I was devastated. I cried on my way home, because I thought the one thing I wanted to do, the one dream I’d always had, the one glimmer of hope I could hold on to, had been taken away from me. I wanted to be a writer but I’d blown it.

A “U”. So I didn’t become a writer, I became a roofer. I consoled myself: at least they both began with an “r”. Roofing didn’t suit me, so I became a jeweller, then a warehouse worker, then a salesman, then… Well, the list goes on up until I was 40 and married, and a policeman. And then one day, I wasn’t.

I was sleeping in my car, with just a dog for company, wondering what happened. I ended up driving a taxi. Giving lifts to the lovers, the lonely and the lager louts in late-night Liverpool. I’d fallen apart but working those long nights started putting me back together. In my mirror I saw thousands of different pairs of eyes staring back at me. And then one night, I realised that each of those pairs, every single one of them, had a story to tell.

All I had to do was ask. So I did. One night there was drunken vicar who said: “I don’t think I’ve ever believed in God, and the hours are a killer…” Another night it was the two pot dealers: “There’s no money in weed since everyone started dealing, and carrying the new stuff makes your tracksuit stink.”

“Me ma has to boil mine.”

“Makes them shrink, lad; costs us a fortune.”

There were the sad stories, like the lady who caught a taxi to the cashpoint at five to midnight on New Year’s Eve. Just so she wouldn’t be alone when the world linked arms and started singing “Auld Lang Syne”. We sat and watched some fireworks together, and I remember how surprised I was that her hands were so warm when she wished me “Happy New Year, son” before she went off to have a miserable one of her own.

There was the old man who asked me to wait while he visited his wife: “I’ll only be five minutes, I just want to check she is OK.” We were in the cemetery.

In the small hours there was a lot of time to think about the people I met. All these stories, all these people living unnoticed lives. A thousand tales sliding across my back seat, never to be told. So I started filling notebooks, pen portraits with poor grammar of the people who passed me by. It wasn’t long before I had more notebooks than I’d had when I was a copper.

Facebook Twitter Pinterest ‘In my cab’s mirror I saw thousands of pairs of eyes. Each had a story to tell. All I had to do was ask. So I did’: Tony Schumacher. Photograph: Murdo MacLeod/Observer

I had no plans until one night, the editor of Liverpool Confidential magazine got in and I chanced my hand. “I do a bit of writing,” I said, lying through my teeth.

“What about?”

“What happens in the cab – you see all sorts in ’ere.”

“Send me some tomorrow. I’ll have a read.”

I went home and wrote a story, and it changed my life. I wrote about the young girl who was being beaten by her boyfriend. I wrote about the mother and daughter taking payday loans to reach the next payday, and then taking a payday loan to… Well, you get the picture. I wrote them all; I told their stories.

And then I started to write a book. I created a British copper who’d lost it all, his wife, his kid, his house, his job, and his soul.

The Darkest Hour is out now (William Morrow, £7.99). To order a copy for £6.39, go to bookshop.theguardian.com