Rodney Mullen via huphtur/wired

In 2003, a lifetime’s worth of violent collisions with the ground finally caught up with Mullen’s body: his right hip fused to his femur, a condition that made it difficult for him to walk, let alone skate.

He sank into a deep depression, intensified by the fact that his marriage to a former World Industries saleswoman was beginning to fail. “I was so afraid of ‘This is my life, who am I without a skateboard?’” he recalls. “Do I even know that guy? Because that’s been me since I was a kid.” Loath for other skaters to see him in such dire shape, Mullen retreated from public life and bunkered down in his house.

When doctors declared themselves stymied by his injury, Mullen elected to engage in a painful form of self-treatment: He pummeled his leg with wrenches and knife handles in an attempt to break up the scar tissue that was strangling his bones. The process was so agonizing that Mullen often had to drive out to remote areas so that no one could hear his screams. He kept at it because it yielded results, albeit slowly—Mullen knew that it would take him several years to get back to full health.

Desperate for a mental diversion as he rehabbed, Mullen cast about for a constructive hobby. The one he settled on would change the course of his life: mastering Linux.