The book is not about mistakes or learning from mistakes, but our favorite subject makes more than one appearance. Here's a short excerpt:
No matter how skilled people are, or how well designed and well executed the projects, problems and failures are inevitable in complex, creative work. We found that inner work life was much more positive when problems were faced squarely, analyzed, and met with plans to overcome or learn from them. Inner work life faltered when problems were ignored, punished, or handled haphazardly.
Learning from success mattered, too. Our participants' thoughts, feelings, and drives fared better when successes, even small ones, were celebrated and then analyzed for knowledge gained. They fared worse when success was ignored, or when its true value was questioned. [p 106]