What’s striking about David A. Price’s history of Pixar, the computer animation studio behind “Toy Story,” “The Incredibles” and other movies, is how provisional it all seemed in the moment, how key players at important junctures didn’t really understand what they were doing even as they were doing it. But they kept working because of a sixth sense that something would eventually happen.
I think that's a good description of a lot of entrepreneurial endeavors. It's also why it's unhealthy (at least in my opinion) for early-stage projects to adhere too closely to a plan: you may have a sense of direction but you may not know exactly what the concrete opportunity is. You have to be comfortable with the uncertainty.