the.com/commonness

means The state of occurring frequently or being widely shared, so familiar it stops registering as remarkable.

from Built straightforwardly from 'common' (from Latin communis, 'shared by all, public') plus the noun-forming suffix '-ness.' Communis itself fuses com- ('together') with a root related to munia ('duties, services'), so the deep sense is of something held or shouldered jointly — what belongs to everyone ends up noticed by no one.