the.com/adage
A truth so old nobody remembers who first stole it.
means A short, time-tested saying expressing a general truth or piece of folk wisdom.
from From Latin adagium, roughly the words on people's lips, blended from ad (to) and an old root for speech — wisdom worn smooth by centuries of mouths.
ErasmusHis 1500 Adagia collected thousands of classical proverbs.
Old by ruleA saying isn't an adage until time approves it.
CousinsMaxim, proverb, aphorism — same family, different formality.