This is truly a great reference book for software craftsmanship.
Initially Dave gives the story about his experience of software craftsmanship. Then the definitions of software craftsmanship, being an apprentice, being a journeyman, being a master are given. Also apprenticeship and apprenticeship pattern are introduced. In following chapters, Dave and Ade use Context-Problem-Solution-Action pattern to address different situations we may encounter in our programming life. Every situation is a signal to improve ourselves and this book points "how-to" when we are stuck in these situations.
To be level up, we need to forget who we are first (emptying the cup). Then think about what we want and the long-term goal (walking the long road). Once the direction is chosen, just do it and don't be afraid of failures (accurate self-assessment). There is no really end of software craftsmanship, and all we could do is to get better and better in our whole life (perpetual learning, construct your curriculum).
In Chinese Kong-Fu, there are two categories. One is to train our skill, and the other is to train our mind. "Apprenticeship Patterns" is more like the latter category. Instead of hard skills, this book gives us some guidances in each stage of software craftsmanship on self-improvement.