08/27/2012 08:53 pm ET Updated Oct 27, 2012

What Can an Angry Bull Teach You About Your Brain's Potential?

One warm August morning the neuroscientist Oliver Sacks set off to hike up a mountainside. He was a young man then, an adventurer in his prime, and he found that the foothills along the way were just rugged enough to get his blood pumping. Eager to test his prowess, he tackled the path's first few turns with ease, barely noticing the warning sign: "Beware of the Bull!"

A few path curves later he met the bull face to snout. The great white beast was napping in the center of the trail, but at first sight of Sacks, it leaped up, tossing its horns and snorting a warning. Its hoof stomped the dust. Sacks spun on his heel and ran -- or, rather, fell, because the next thing he knew, he was lying at the bottom of a rocky crevasse, his left leg bent beneath him at an impossible angle, his knee throbbing with a pain that blotted out coherent thought.

At that moment, Sacks says, his mind suddenly entered a state he'd read about but never fully understood: a detachment from his own body, a clinical lack of emotion that gave him an observer's perspective on his injury. Lecturing quietly to himself, as if to a roomful of medical students, he examined the kneecap torn from his moorings, the ribbons of unresponsive muscle, the swollen blotches of burst arteries. With the smile of a true geek at work, he announced his diagnosis: "Muscle paralyzed and atonic -- probably nerve injury. Unstable knee joint -- seems to dislocate backward. Possible bone injury -- easily one or more fractures. Considerable swelling..."

And then reality finally set in: He was trapped halfway up a mountain in a lonely wilderness where, despite the summer season, temperatures routinely fell below freezing after dark. If he spent the night here, he'd be dead by morning.

That realization shifted his mind's gears yet again. Over the next several hours, Sacks recalls, he watched his mind and body cycle through a whole repertoire of "backup programs" he'd never known he had. Somehow he managed to fashion a splint out of an umbrella he'd been using as a walking stick, and he set off down the trail, hardly conscious of his situation, scarcely aware of more than the singsong rhymes that began echoing in his thoughts, setting the rhythm of his limping steps: One-and-two-and-one-and-two...

As he struggled across a frigid stream, he heard a voice in his mind shouting, "Hold on for dear life! I'll kill you if you let go!" And then it was he who shouted those words at himself. And then, again, he heard the shouting and obeyed its commands. He was nothing more than muscle and bone and pain and a will to keep moving forward, so that's what he did.

By the time he regained sight of civilization (in the form of a small hillside village), Sacks felt flooded with euphoria, exhilarated simply to breathe, to limp along, to feel the cool breeze on his face and watch the setting sun. He resisted a powerful urge to lie down and nap; instead, he kept hiking until he reached the foothills, where he called out to a distant huntsman who happened to be crossing the trail. The hunter shared a canteen of water and a flask of something stronger, then he left Sacks in the care of his teenage son while he ran to the village for help.

The stars were coming out now. The young adventurer huddled in a warm blanket and beamed with joy: He'd survived.

What can we learn from Sacks' experience (other than, you know, to pay attention to warnings about dangerous animals, and to avoid hiking up desolate mountains alone)? Three morals come to mind. First, we humans are built to survive trauma; our brains and muscles come pre-loaded with survival instincts honed by millions of years of natural selection. Second, we modern humans rarely experience those instincts in the personal, visceral way that they filled the daily lives of our early ancestors. And third (a point contingent on the first two), your mind and body are capable of much greater resourcefulness than you think.

As Bruce Lee famously said, "There are plateaus, but you must not stay there; you must go beyond them. A man must constantly exceed his level." What about you: Have you exceeded your level today?