“The best revenge is not to be like your enemy.”
Marcus Aurelius.
From Wikipedia:
"Marcus Aurelius was Roman emperor from 161 to 180. He ruled with his adoptive brother, Lucius Verus, until Verus' death in 169, and with his son, Commodus, from 177.
He was the last of the so-called Five Good Emperors".
He is best known for his Meditations on Stoic philosophy.
(Stoic philosophy teaches self-control development as a means of overcoming destructive emotions).