Moreover, not all of the identified "rudeness" is actually rude; it's just different customs.
I knew the rudeness I was committing, but still I rose and left the church.
The Daily Pic: The great Bruce Nauman doubles-down on rudeness, and defeats it.
late 13c., "coarse, rough" (of surfaces), from Old French ruide (13c.) or directly from Latin rudis "rough, crude, unlearned," perhaps related to rudus "rubble." Sense of "ill-mannered, uncultured; uneducated, uncultured" is from mid-14c. Rude boy (also rudie, for short) in Jamaican slang is attested from 1967. Figurative phrase rude awakening is attested from 1895.