So Good They Can't Ignore You by Cal Newport (craftsman mindset)
Computer science professor Cal Newport pushes back on the popular advice to 'follow your passion'. His research found that most people who love their work did not start with a passion. They built rare and valuable skills first, and passion followed as they got good.
He calls this the craftsman mindset: instead of asking 'what can this work give me?', you ask 'what am I becoming good at, and how valuable is that?'. Skill, in his phrase, is 'career capital'. You build it up, then trade it for autonomy, impact and interesting work.
The practical consequence: a business idea is stronger when it sits on a skill you have already invested thousands of hours in, or one you are genuinely willing to grind at for 6 to 12 months before it pays. 'I'm passionate about it' on its own is not an edge.
Where this shows up in the quiz
Step 5 is this book applied. You name the one skill your business would run on, then answer four questions about how deep that skill already goes, whether it is rare, and whether you would keep doing it unpaid.