One of my hobbies used to be brutal enduro-hiking, and my little trip up Rainier years ago still stands out in my memory as the hardest thing I've ever done.
If HN readers really need that entrepreneur spin on this, then I'd suggest that there are a lot of parallels between summiting (and knowing when not to summit) and entrepreneurship.
Everest specifically is probably more because it's a trophy; there are a lot of mountains out there that would afford a pretty similar challenge.