Revenge is a mistake built upon another mistake. The first mistake was, “He took it from me—my peace, my pride, my respectability.” That was the first mistake to think that way. And the second mistake is, “I can get peace back by snatching it away from him.”
Revenge is: thinking that a fall can compensate for another fall.
A drunkard falls to his left and his left bum is paining, so he says, “This is instability, lack of equilibrium.” So, to make good of the matters, what does he do? He falls to the right. He says, “Now it is stable.” This is what the scriptures have called as equanimity, sambhāva : both the bums should hurt equally!