<p>In 2013, an Australian man a few months shy of turning 60 decided to walk the Camino de Santiago – an 800km pilgrimage trail across the top of Spain. He had no known religion, and absolutely no idea why he felt so deeply compelled to do this torturous walk.<br/> But compelled, he was.<br/> He completed the walk, battling a “triumvirate of pain” - a knee that he later discovered lacked any meaningful cartilage, a blister the sight of which would make a grown man weep, and shin-soreness that