This amazing YouTube video feature two people living on the edge. Steph Davis and Dean Potter are world-class rock climbers. They climb some of the most imposing rocks on earth. And they do it without ropes.

Climbing without safety equipment is known as Free-solo Climbing. It’s dangerous. One mistake equals death. It requires a mastery of your body. You also have to know every climbing trick in the book.

These climbers know that they must be in peak physical form. But they also know that their mindset may be even more important.