There's a constant tension in climbing, and really all exploration, between pushing yourself into the unknown but trying not to push too far. The best any of us can do is to tread that line carefully.

We are apes - we should be climbing.

I've never really understood the criticism that climbing is inherently selfish, since it could equally be argued about virtually any other hobby or sport. Is gardening selfish?

In a general sense, I think it's bad to bring too much money into climbing, since it takes away a little from the beauty of the mountains. But at the same time, I can't blame the Nepali government - or the Indian, Pakistani or Chinese, depending on where you're climbing - from wanting to capitalize on foreign climbers.

Yosemite has the most impressive and accessible granite big walls in the world. The rock is amazing. And because of that, it's been the mecca for climbing in the U.S. - and the world to a large degree - for all of climbing history. It's the place to test yourself against the historic routes of the past.

I'm not thinking about anything when I'm climbing, which is part of the appeal. I'm focused on executing what's in front of me.