At the age of 15 I left my school and my home in south London and went to work as a farm labourer on the edge of Exmoor in the wilds of West Somerset. I fell in love with the life of the country, getting up before dawn and working until the evening. And when the hunt was meeting I rode second horse for my boss with the Devon and Somerset stag hounds. The life was all magic to me.

A year later, when the magic had become my routine, a fine-looking horseman rode into the wintry field where I was digging turnip shells for the sheep. He stopped beside me, his beautiful horse excited and uneasy with my closeness, and he said hello. This was unusual. But he was an Australian, my first. He had come to England with the dream of retiring to the life of an English hunting gentleman, but had soon discovered he was out of place. On Exmoor the locals viewed him with distrust as an oddity and an outsider. I was an outsider myself, and possibly his last resort for someone to chat to. A couple of weeks after he came into the turnip field I was drinking a cup of tea with my new Australian friend and his wife in their kitchen. He got up from the table and fetched a book. If it's the wild frontiers of this world you want to see, he said, you should read this.

The book contained a bewitching account of the Australian artist Sidney Nolan's journey into the outback of North Queensland. The year was 1953 and the name Nolan meant nothing to me, but the fine black-and-white silver gelatin photographs captivated me. As the months went by, my romantic dream of reaching Nolan's outback persisted. I was convinced that in such a grand and unlikely journey I had found an epic purpose for my life. Almost a year later my family stood on the platform at Liverpool Street station, waving me off for Tilbury and the other side of the world. I was not to see them again for 10 years.

When I got off the boat in Sydney six weeks later I was still underage and was supposed to report my arrival in Australia to the authorities. But I was too impatient to reach the outback, and I set off at once with my suitcase. Walking north along the highway I thumbed down a truck. The driver was friendly. My story did not surprise him. "You're doing the right thing, old mate," he said. "I should have done it when I was your age."

He drove me to the southern Queensland coastal town of Gympie and got me a job on a dairy farm. The truck driver and I had become friends of the road and he had led me into the way of being Australian. It wasn't difficult for me. My mother's people were Irish and my father was from Glasgow – my parents' cultures the very ones from which the majority of white Australians had their origins. Being Australian felt more natural to me than trying to be English ever had. With an intuitive certainty that is only available to us when we are young, I knew that my arrival on the other side of the world had been a homecoming.

Gympie was hot, the vegetation sub-tropical; fierce taipans lurked among the flowering lantana and death adders sunned themselves along the riverbank when we went for a swim. It fascinated me, but it was only a stop along the way. A dairy farm in Gympie was not Nolan's outback. After a few months I showed my book to the farmer and his wife and told them my dream. They offered to help me with the next stage of the journey. They had never been to the outback, they said. "Will you tell us what it's like?" I promised I would write. But I never did. With that leave-taking I was beginning to accumulate my grown-up store of small regrets. There would be occasions for larger ones later.

He was gentlemanly and had about him an interesting air of melancholy, which I thought at once had something to do with solitariness. He liked to drink Pedro Ximenez black sherry in front of the fire in the evening – or even during the afternoon – and he loved to read. He was the owner of a 64,000-acre cattle station in the open ironbark forests of the Central Highlands of Queensland, his domain set deep among the wild granite escarpments of the Carnarvon range, his pastures watered by the abundant stream of Coona creek. He was my new boss. I was shy with his youthful wife and addressed her respectfully as Mrs Wells, while I dreamed of being her lover. He insisted I call him Reg. There was little to be done on the station just then, he said, and he gazed out from the front verandah at the silver grass of the plain and the dark forests beyond and the rim of fortress hills, as if he dreamed of being somewhere else. I explored the wilderness on horseback, camping on my own for days high in the escarpments, where the dingoes were so wild they had no fear of me.

At Christmas, Reg said I should fight in the boxing tournament in Springsure to raise money for the Red Cross, and I reluctantly obeyed. With more enthusiasm I rode in the bareback and saddle bronc events in the rodeo, as all the other young stockmen of the district did. When autumn came we mustered the half-wild cattle then drove the steers to the market, riding behind the mob at an easy walk, making our eight-mile stage along the stock route each day. And in the sandhill country I smelled the heady perfume of the wattle scrubs in bloom. Reg and I camped under the stars, lying in our swags beside our fire, I talking of my dreams and he of his disenchantments.

I loved it on Goathlands Station with Reg and his family, so stayed longer than I intended. He had been delighted to discover I could shoe horses and ride, but it was not station work that was his first love. Before anything else I learnt from Reg Wells the pleasure of reading, and something of its art. After two years I told him: "It's only that you've been so kind to me that I've stayed this long."

He smiled; he'd known he'd lose me one day. He radioed his old friend, the manager of a vast cattle station in the remote Gulf of Carpentaria, a tract of country bigger than Wales. I shook hands with Reg at the Springsure railway station, the family gathered to see me off. I was leaving behind me a scene that recalled my other, earlier farewell at Liverpool Street. This time I was more emotional. This time I had doubts. This time I wondered if what I was leaving behind might not be the very thing I had set out in search of.

Three days out of Springsure on slow trains took me to the far western cattle town of Cloncurry, a huddle of pubs and stores stained with the monochrome dust of the landscape. I picked up the mail coach, an old army blitz wagon loaded with drums of fuel and stores for the stations along the Leichhardt river, and rode it the 300 miles north to Augustus Downs station. There was no road, just wheel tracks through the savannah. Where these crossed the waterless bed of the river the mailman picked his own way among the rocks and treacherous sands.

The manager of Augustus Downs drove his jeep at high speed across the plain for 60 miles. There were no fences. This was Nolan's outback. The cattle camp was a tent fly and a smoking fire among the timber on the bank of the Leichhardt. Under the fly a man was kneading dough on a board. When I greeted him he went on, mumbling to himself, ignoring me. Towards evening a group of about 30 horsemen rode into the camp, raising a cloud of dust. They formed a half-circle round me, not smiling nor offering a greeting. Two of them were white, the others were black, their hair and beards long and unkempt, their broad-brimmed hats and mounts covered with the same dust that had clothed the buildings of the town. One of them stepped his horse out of the half-circle towards me and sat looking down at me.

"You English?" he said, as if he was challenging this very possibility. I said I was. He spat aside. "Where's your English saddle?" I told him I didn't have one. There was a brief silence, then he laughed as if he had been had, and all the others laughed and they spun their horses and cantered into the timber laughing. They were the legendary ringers of the great plains of the Gulf of Carpentaria. Tribal Aborigines on their own country. We became friends. But at the end of the season I left the Gulf. I knew I would never belong in that country. Not as the Aboriginal stockmen belonged in it. No matter how welcome they made me, I'd always be passing through on my way to somewhere else. And passing through on my way to somewhere else wasn't the life I wanted.

After I left the Gulf I did not know where to go. For some years I was lost. Nolan's outback had not answered something for me, but had faced me with my biggest question: how was I to make sense of my life? In a boarding house for single men in the southern city of Melbourne I began to write of my uncertainties. Writing seemed my only way forward out of the despair into which I had sunk. Reg Wells made a reader of me, but it was Nolan's outback that made me a writer.

Alex Miller's latest novel Lovesong, is published this month by Allen & Unwin, £7.99. He lives in Victoria with his wife and two children. To buy this book, go to guardianbookshop.co.uk