It was even odds that the thing I was the most afraid of didn't actually exist at all. - Steven Kotler

Scientists who study human motivation have lately learned that after basic survival needs have been met, the combination of autonomy (the desire to direct your own life), mastery (the desire to learn, explore, and be creative), and purpose (the desire to matter, to contribute to the world) are our most powerful intrinsic drivers — the three things that motivate us most. All three are deeply woven through the fabric of flow.

In fact, we’re not smart and we have bodies — we’re smart because we have bodies.7 The heart has about 40,000 neurons that play a central role in shaping emotion, perception, and decision making. The stomach and intestines complete this network, containing more than 500 million nerve cells, 100 million neurons, 30 different neurotransmitters, and 90 percent of the body’s supply of serotonin (one of the major neurochemicals responsible for mood and well-being). This “second brain,” as scientists have dubbed it, lends some empirical support to the persistent notion of gut instinct.

Instead, over the past thirty years, in the world of action and adventure sports, in situations where asses really were on the line, the bounds of the possible have been pushed further and faster than ever before in history. We’ve seen near-exponential growth in ultimate human performance, which is both hyperbolic paradox and considerable mystery. Somehow, a generation’s worth of iconoclastic misfits have rewritten the rules of the feasible, not just raising the bar but often obliterating it altogether. And this brings up one final question: Where–if anywhere–do our actual limits lie?