Correction: In the broadcast version of this interview, Reinhold Messner is incorrectly said to have walked 28,000 kilometers across Antarctica. He walked 2,800 kilometers.

Reinhold Messner is arguably the world’s greatest living mountaineer. He’s climbed 14 of the world’s tallest peaks, and if that isn’t impressive enough, he was the first to climb Mt. Everest alone and without supplemental oxygen. He recounts some of these adventures in a new book called “Reinhold Messner: My Life at the Limit.” Steve Paulson caught up with him and asked how he got hooked on climbing.