When I left the Royal Marines, I led some expeditions for a company called World Challenge, taking groups of teenagers from the UK to foreign lands for a month’s challenge adventure. The groups were mixed gender of varying backgrounds with many different reasons for being there, ranging from ‘I want an adventure’ to ‘It’ll look good on my CV’ to ‘Well, my friend was going so why not?’ Though they all worked on their fitness in the preceding months, it's fair to say there was