– and we could get out of the oppressive cold. Looking around the mud flat it was apparent that some students were about to give up. It was still over eight hours till the sun came up – eight more hours of bone-chilling cold.

The chattering teeth and shivering moans of the trainees were so loud it was hard to hear anything. And then, one voice began to echo through the night, one voice raised in song. The song was terribly out of tune, but sung with great enthusiasm. One voice became two and two became three and before long everyone in the class was sing-ing. We knew that if one man could rise above the misery then others could as well.

The instructors threatened us with more time in the mud if we kept up the singingbut the singing persisted. And somehow the mud seemed a little warmer, the wind a little tamer and the dawn not so far away.

If I have learned anything in my time traveling the world, it is the power of hope. The power of one person – Washington, Lincoln, King, Mandela and even a young girl from Pakistan, Malala – one person can change the world by giving people hope.