It's a great cultural experience.

Did 17 hours of non-stop climbing while I had a stomach bug, directly from the base camp to the summit, (almost two kilometers of vertical climb in freezing temperature and deep snow and ice) and back, with little food and less than two hours of sleep in the 18 hours prior to the start of the climb. Or : Slept in a cave in the wild,solo, for three consecutive nights (there were plenty of bears and snakes in the area).