My colleague Stefni being rescued from the mezzanine by the electrician. (at Krista Tippett Public Productions)
I think of the lessons from Mt. Everest here: summiting is easy. Making it back to base camp is the real test.
As a climber, I can safely say that while from a general mountaineering perspective, the regular route on Everest is considered relatively easy, anything over 8,000m is not a simple walk up for many reasons, even for all but the most skilled and experienced alpinists. But you are very right in noting that half the climb is the descent! A lot can go wrong there as well.