One common thread in this book has been the virtues of actually building something and seeing what goes wrong. A lot of traditional education is focused on walking through the “right way” to do something, heavily implying that the body of knowledge that a teacher is describing sprang up originally in just that form. Anyone who has worked on a real engineering project of any scale knows that it is never that way. Good managers put “margin” in their budgets just for the things that they either did not think of or realize they cannot think of ahead of time because the project is exploring new territory, literally or figuratively. Many big failures occur because someone was surprised by something previously unknown, and so an equally big discovery may ultimately arise from the failure. In Chapters 12 through 14, Joan talks a lot about science and serendipity and how sometimes a scientist is just in the right place at the right time (and trained and disciplined enough to recognize what was going on).