And one of the things that I learned was you can't generalise at all about a woman in a veil. You can't think you know her story, because she will confound you over and over again. She may be an engineer or a diplomat or a doctor. Or she may be an unbelievable babe with bleached hair down to her waist.

I'm a praying atheist. When I hear an ambulance siren, I ask for a blessing for those people in trouble, knowing that no one's listening. I think it's just a habit of mindfulness.

But that Franklin trip changed me profoundly. As I believe wilderness experience changes everyone. Because it puts us in our place. The human place, which our species inhabited for most of its evolutionary life. That place that shaped our psyches and made us who we are. The place where nature is big and we are small.

I think that you can honour the sacrifices of a common soldier without glorifying war.

I think probably the scaredest I've ever been was in Somalia. I arrived there when the episode that became known as 'Black Hawk Down' was still taking place. The Americans were still pinned down under fire. And everybody else was basically going the other way, and I was the only one putting my hand up for a flight in.

I was not 15 anymore, and choices no longer had that same clear, bright edge to them.

You go on. You set one foot in front of the other, and if a thin voice cries out, somewhere behind you, you pretend not to hear, and keep going.