It so happened that I was in the early stages of planning this Walking Home From Mongolia adventure when my previous expedition partner pulled out for family reasons two days before Leon arrived. And so, a few days later, after getting to know Leon a bit better and gaining respect for both his camerawork and adventuring ability, I invited him to join me on the trek.

Any serious adventurer will now perhaps remark that asking someone I barely knew to come on a long, gruelling and risky journey was a rash thing to do. Indeed, many an expedition has come undone owing to team members falling out, even when they are old friends. By the time Peter Hillary and Graeme Dingle finished walking the length of the Himalayas in 1981, they were almost unable to speak to each other. On his 860-day walk across the Amazon, Ed Stafford's expedition partner left him after just three months. The list goes on.

British adventurer Ranulph Fiennes has said how rare it has been for him to find reliable teammates, and has a general rule of 'never selecting Yorkshiremen for my teams, because they are dour and nurse grievances; small men, because they need to work hard to make themselves seen and heard; and spectacled men because, when their spectacles break, they may become pains in the neck'.

I guess big bust-ups should be expected in an environment that combines the big egos and ambitions of adventurers with severe conditions, regular dangers, complex logistical decisions and tricky deadlines.

It's sometimes easier and better to travel alone. For the vast majority of my three-year Cycling Home From Siberia expedition, I was by myself, and I think this enabled me to learn more, grow up more, and also make friends with and receive hospitality from locals more easily.

However, there are also some very good reasons to pair up. It's certainly safer (if one person is sick or injured); less scary (when facing a perceived danger); and better for documenting with film and photos.

So, how have Leon and I fared? So far, pretty well. Much of the credit for this must go to Leon, who is an intelligent, patient, tough and easy-going guy, who does not harbour delusions of grandeur and has the guts to have difficult conversations early on and admit when he is wrong.

When we set off into the Gobi, Leon had no hesitation in getting the camera out and removing his gloves to set the controls, even when it was a blistering minus 20 degrees Celsius. He would then cheerfully take his turn dragging our trailer through the desert, singing loudly along to Red Hot Chilli Peppers on his iPod. He has been quick to try and find solutions to various problems we encounter, and is so optimistic at times that I now call him a 'hopevist'.

At the same time, we've had a number of disagreements: on the route, estimated day of arrival and how much water to carry. Usually, we get through these by debating them as we hike, before coming to some kind of resolution.

More serious, however, are the petty irritations. For example, Leon gets annoyed that I'm not a morning person and so take longer to get ready in the morning, which means we set off late and have to hike into the dark to reach our destination. I get annoyed that he gets ready so quickly.

To deal with such things, it has been essential for us to talk through the problems early, before they grow into full-blown resentments (this principle is very helpful in marriage, too). We've also given each other space by taking two tents instead of one and spending our days off apart to do our own thing.

So, with 20 per cent of the journey done, we're getting on well. I hope it continues this way. It needs to if we are going to make it past the many challenges that still await us on our long walk home.