if everyone has it, it ceases to have any significance, and can be ignored. this is why someone might have been called "johnny 1 leg", because he only had one

if everyone has it, it ceases to have any significance, and can be ignored. this is why someone might have been called "johnny 1 leg", because he only had one leg. You do not hear things like "2 legs 2 arms 10 fingers 1 heart 1 bellybutton johnny"