Cub Driver wrote:

I have been skiing at Ajax (Aspen Mountain) on a regular basis for
nearly forty years and have never noticed any effect on mental acuity
at 11,000 feet.

It is the very nature of hypoxia that you don't recognize it yourself.
Actually, this is the point which makes it so dangerous. I'm somewhat
shocked that a pilot wouldn't know this.

Of course it may be that skiers are mentally inacute
to begin with.

One thing is to walk around (or ski around or climb around, for that
matter). It's a very different thing to work mentally, as is piloting.

Stefan