Antoine de Saint-Exupery wrote in WIND,SAND AND STARS about his first mail flight. His pilot mentor didn't discuss grand things on the chart, but the unseen little stream on one 'landing strip' that could flip a Breguet and three trees on another.
Walkers know things drivers do not; dangerous dogs,one parallel road with a subtle, but exausting grade and gravel sidewalks, where the public bathrooms are.