As many people did along the trail to Glacier Point, a couple women cross-country skiing asked about the sled and what we were doing. After explaining the ITI and our training as best I could, one of them asked the inevitable question.
Woman: "Why are you doing it?"
Me: "It's hard to explain. Why do people climb mountains?"
Woman (with a little chuckle): "Oh, you mean 'because it's there'?"
Me: "No, not really. I mean, the mountain will still be there whether anyone climbs it or not. You climb it to see if you can."