This short post continues my series of searching for explanations of what drives people to challenge themselves physically and mentally through journeys, challenges, races, expeditions and adventures.
I have been re-reading Thesiger recently, and he has this to say,

For years the Empty Quarter had represented to me the final, unattainable challenge which the desert offered. Suddenly it had come within my reach. I remembered my excitement when casually offered me the chance to go there, the immediate determination to cross it, and then the doubts and fears, the frustrations, and the moments of despair. Now I had crossed it.
To others my journey would have little importance. It would produce nothing except a rather inaccurate map which no one was ever likely to use. It was a personal experience, and the reward had been a drink of clean, nearly tasteless water. I was content with that.
Looking back on the journey I realised that there had been no high moment of achievement such as a mountaineer must feel when he stands upon his chosen summit.

I’mm compiling a little list of these answers to the question Why? here on my Encouragement page.