So, something about nerve issues. (The red thing that looks like a wart is actually a scar from a cut right at the bend of the knuckle)

My very fingertips up to the green line are nerve-blank. That’s fine; I’m rough with them sometimes for pride and fun, it mildly limits my ability to pick my nose, pick up paper off a flat surface, or pry things with my fingernails.

On bad days, however, there’s some numbing all the way back to the red line, at which point I can’t use feeling to guide my grasp on the finer flaps of paper or plastic packaging and have to just rip it open like a barbarian

Like when they talked about surgeons or pianists having “smart” fingers it was just that in an agrarian/industrial world they hadn’t accumulated any damage