After retiring from his eighth startup, Blank found himself in a ski cabin reflecting on twenty-one years in Silicon Valley. What started as an attempt at memoirs led to a revelation: business schools and investors had been treating startups like small versions of large companies, but startups were actually something completely different—they were explorers searching for unknown customers, markets, and business models. Every smart professor at Harvard, Wharton, and Stanford believed otherwise. Blank could have dismissed his own insight, but instead he persisted. He nagged Berkeley's business school into letting him teach a new course based on his ideas, and then Stanford's engineering school followed. A decade later, that course—Customer Development—had become the foundation of an entirely new way to start companies. His advice to the graduates was drawn from lived experience: when you see something that others don't, the world will tell you you're wrong. Ignore them.