Neal Stephenson on Entrepreneurship

"...the idea being that all the training in the world was of no use, maybe even worse than useless, if you did not know when to use it, and knowing when to use it was a lot harder than it sounded, because sometimes, if you waited too long to go into action, it was too late, and other times, if you did it too early, you only made matters worse."

—Neal Stephenson, Anathem, p. 490

OK, maybe he isn't talking about entrepreneurship per se, but it certainly seems applicable.