When a man tells you about the time he planned to put a vegetable garden on Mars, you worry about his mental state. But if that same man has since launched multiple rockets that are actually capable of reaching Mars—sending them into orbit, Bond-style, from a tiny island in the Pacific—you need to find another diagnosis. That’s the thing about extreme entrepreneurialism: There’s a fine line between madness and genius, and you need a little bit of both to really change the world.All entrepreneurs have an aptitude for risk, but more important than that is their capacity for self-delusion. Indeed, psychological investigations have found that entrepreneurs aren’t more risk-tolerant than non-entrepreneurs. They just have an extraordinary ability to believe in their own visions, so much so that they think what they’re embarking on isn’t really that risky. They’re wrong, of course, but without the ability to be so wrong—to willfully ignore all those naysayers and all that evidence to the contrary—no one would possess the necessary audacity to start something radically new.