Towards the end of November 2011 I stood on the frozen Ross Ice Shelf of the Antarctic coast.

The plane that had brought me there quickly became a tiny black blob in the sky. I could still hear the distinctive drone of its engines but with every breath the sound became fainter. I closed my eyes to focus my ears on the noise but it was slowly, and inevitably, blotted out by the silence. When I opened my eyes again, the plane had gone. I was alone.

I stood motionless for a second, breathing in the cold air. Even the smallest of movements sounded brutally intrusive in the stillness: the rasp of brittle fabrics, the polystyrene squeak of my boots in the snow. I turned on the spot, running my gaze slowly over the horizon, trying to take in my surroundings. To my right was the flat expanse of the Ross Ice Shelf, a featureless divide of white snow and blue sky, while to my left were the Transantarctic Mountains which extended in an unbroken line as far as I could see in either direction. Each peak appeared intimately close-by even though I knew that I could travel for hours towards them and still not touch stone.

As I looked around me, one thought echoed through my brain: in all this landscape, in all this space, I was the only living thing. I could search every fold of rock, every block of ice and not find so much as a nesting bird, a minute fly or a single blade of hardy grass. The nearest open water where any wildlife was to be found was more than 700 kilometres away to the north. The scale of the emptiness was almost too much to absorb.

Panic filled my chest and I felt choked. It wasn’t that I feared for my life or for my safety, it was the alone-ness itself that scared me. I have always been comfortable in my own company and often travel by myself to remote places but this was a whole new level of isolation. Ahead of me was a 1700km ski journey across the entire Antarctica continent – a journey that would eventually take me 59-days to complete, making me the first woman ever to do so alone. But, during those first moments of the expedition as I stood contemplating the challenges ahead - the cold, the altitude, the crevasses, the terrain – it was the alone-ness that was most daunting.

Every morning I would wake up listening to the wind whistling past the tent and I’d be filled with a deadening conviction; I couldn’t go on. Antarctica was more than I could manage on my own. I knew that it was impossible for me to get out of the tent and confront the remorseless weather that waited for me. I could not spend another day battling forward on my skis trying to ignore the clammy discomfort of the close fitting material around my face protecting my skin from freezing. I could not bear anymore the moment I would be forced to expose myself to the cold, hastily refastening stubborn clothing with painfully numbing fingers, only to repeat the agonising process a few hours later. The relentless struggle just to stay safe, never mind move forward, was more than I could take. I understood, in that moment, categorically, that the distance ahead of me and the number of days to come, as well as my alone-ness, was more, much more, than I could face. It wasn’t that I was giving in; it was a calm and rational realisation that I didn’t have the physical or mental capacity for the challenge ahead. I had found what I had come to Antarctica for. I had found my limit.

And yet every morning I would have to get myself out of that mind set and find a way to motivate myself. Often it wasn’t pretty; it usually involved a lot of crying, a lot of cajoling and a lot of painful angst. I found that it was remembering those who had been disparaging of me in the past, or events that had left me feeling angry and indignant, that provided the greatest incentive. I made old wounds fresh by recalling those who had dismissed me, people who had been unjustly harsh in their evaluation of my character and my capability, in order to galvanise myself. At first I felt a little embarrassed at this way of going about things; but perhaps it is natural that the strongest feelings provoke the most dramatic responses and hurt so often stays with us longer and more vividly than praise.

I realised that the success or failure of my expedition was not going to be down to anything heroic; it was not about ploughing through blizzards, crossing crevasses or dealing with frostbite – it would come down to the simple, fundamental and yet very difficult challenge of getting out of the tent each and every morning.

When I returned home, having completed my expedition, I found that this part of my experience struck a chord with lots of people – what is it that keeps us going even when we know it is impossible to continue? The fact that I had crossed Antarctica, despite the tears and the fear and the alone-ness, deepened my belief that we are each far more capable than we give ourselves credit for. Our bodies are stronger and our minds more resilient than we could ever imagine. All you have to do is keep getting out of that tent…