This seems to be particularly polarizing. I take the doc as an effort to distill practice, user stories, and a little bit of background theory as required to ke

This seems to be particularly polarizing. I take the doc as an effort to distill practice, user stories, and a little bit of background theory as required to keep things varied an interesting to various types of learners. There's the rote memorization (do hasty search not a horizon scan), and theory-to-practice (rods and cones for nighttime visual search). I also imagine that the intended audience for this book has not been exposed to some of the biological underpinnings of senses, and never had an explanation for why it was difficult to resolve colors in darkness. That facts are placed right next to actionable workarounds and right next to observable consequences is a pretty good writing strategy to educate practitioners. I can imagine (but have not experienced) some useful rules of thumb coming from this document that are pounded into minds until they are second nature. Range estimation, hasty search + follow-up search, rough ranges at which cigarettes are visible in darkness, speech is audible, and so on. That's gold for its indented audience.