My first great journey was, in the scheme of things, not that great after all. It was a school excursion by plane and coach to Hobart from Melbourne.
I was no Isabelle Eberhardt, who roamed the 19th-century Arab world dressed as a man. I travelled with a gaggle of school friends and two teachers and the wildest things we saw were Tasmanian devils behind a fence.
Nor was it exactly intrepid, although the Cadbury's factory, in the days when samples were handed out extravagantly, offered plenty of calorific dangers and made chocolate addicts out of us all.
It was not a heroic trip on an Odyssian scale, but it was the first time I travelled away from home, flew on a plane, crossed a sea and slept in a hotel bed (the old Astor in Hobart.) In years to come, I would cross deserts, too, and sail in ships that battled 10-metre seas, but the great journey to Hobart with all its "firsts" counts as one of my favourite adventures.
We might think of a great journey as a physical one that consumes time and much effort, traversing continents by foot and other means, climbing mountains, hiking plains, sailing around blustery capes, or plunging into wild and unknown territories.
There are journeys for the physically adventurous – riding the Trans Siberian railway, joining the 35-day pilgrimage to Santiago de Compostela, trekking across the Sahara Desert, biking the Congo Nile Trail, hiking the Inca Trail, climbing Mount Kilimanjaro.
There are journeys of a more inspirational kind, which follow in the footsteps of a favourite author or artist – Paul and Jane Bowles' Morocco, Gauguin's Tahiti, Gabriel Garcia Marquez's Colombia, Hemingway's Cuba perhaps.
And there are journeys of the interior kind. Before she left war-scarred Europe on her first trip to New York in 1947, French author Simone de Beauvoir wrote, "I feel I'm leaving my life behind. I don't know if it will be through anger or hope, but something is going to be revealed – a world so full, so rich, and so unexpected that I'll have the extraordinary adventure of becoming a different me."
I don't think a journey can be truly "great" unless it is all these things – inspirational, emotional and transformational as much as it is physical. Some trips are enjoyable and fun but don't resonate beyond those moments; others deeply affect people for the rest of their lives.
I have been thinking about all the wonderful journeys I have been on throughout my life and those that I value the most are those where I felt something changed in me and my understanding of the world and humanity at large, through my exposure to new people and ideas and to majestic landscapes where I felt a sense of myself as a small part of a greater natural universe.
The best journeys had an element of risk or the unknown to them. When I went to China in 1984, the entire two-week trip, while organised by a China expert, was chaotic, arduous and sometimes terrifying, especially the notoriously unsafe internal flights and the presence of military everywhere.
But how could I forget the Great Wall when there were few people on it, or arriving in a country where everyone wore the same uniform, or herding buffalo in the feudal countryside for a photograph?
In China in 1984 I saw things I had never seen before, but I also came back humbled by the familiarity of the exotic. Even within a culture that was completely alien to me I found much in common with the people I met. Our tour guide, a young woman just out of university, could easily have been an Australian graduate – she had the same desires for herself that any Australian young woman might have. This was pre-Tiananmen Square and you could see that a major disruption was coming.
So that great journey taught me about politics as well as humanitarian issues. It was a difficult trip but great journeys often are, demanding courage, even if at a modest level.
These days there are many, many companies who will package your great journey for you and fill brochures with the words "inspiring" and "life-changing". The whole world is accessible, so few of us will forge new territory like the 19th-century adventurers. But all of us have our own "unknowns". A great journey begins and ends with the desire to confront those.