We are apes - we should be climbing.

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.

I have a journal of everything I've ever climbed since 2005. For the entry about free soloing Half Dome, I put a frowny face and added some little notes about what I should have done better, and then underlined it. Turns out that is one of my biggest climbing achievements.

I've tried to approach environmentalism the same way I do my climbing: by setting small, concrete goals that build on each other.

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?

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.