The book is about bridging the huge gaps between what engineers know, what they do and why things go wrong. It puts engineering into a wider perspective so readers can see how it relates to other disciplines - especially science and technology. Many intellectuals have dismissed engineering as 'applied science', but this book shows how wrong it is to do so - engineers apply science, but their purpose is quite different.It takes the reader on a learning journey of reflections on the gaps between theory and practice in professional life - not just in engineering but across all disciplines. The learning is summarized through 20 learning points or lessons, each one placed in context. Some of the important lessons are about learning from failure, joining-up theory and practice, understanding process, classifying uncertainty, managing risks, finding resilience, thinking systems to improve performance and nurturing practical wisdom.