Everyone knows lots of stuff, or thinks they do.
For example, I've been told that adaptation to altitude is different than just having good wind due to cardiovascular exercise. I've also been told the opposite. My own experience has supported the first theory. Some years ago I climbed Rainier with a group that included some pretty fit folks, including a marathon runner. At the time I trained by watching TV, smoking 2 packs of Kools a day, and living at sea level. I doubt that I could have run a quarter mile without stopping for breath.
I was the only one of the group who did not feel sick once we got above camp Shurman, and was the only one who felt good enough to climb past the schrund to the top. Since the climb was part of an AMS experiment, we all ate the same food & drank lots of water, so whatever made the difference it wasn't cardiovascular fitness.
If you look back at the posts you'll notice a variety of opinions, and nobody save mneagle has put forth any credentials. And I don't know what Layton posted; he's been on my ignore list for a long time.