Mount Everest, known to all, understood by few – including someone who has been up and down the treacherous peak almost 20 times. More than 7,500 individuals have reached the top of the highest mountain on Earth since it was first conquered by Edmund Hillary and Tenzing Norgay on May 29, 1953, and there have been more than 15,780 successful ascents, with climbers and guides returning for repeated attempts. It has also claimed the lives of at least 346 people, which is the number since records...