You're thinking that people don't keep up old jealousies for twenty years or so. Perhaps not. Not just primitive, brute jealousy. That means a word and a blow. But the thing that rankles is hurt vanity. That sticks. Humiliation. And we've all got a sore spot we don't like to have touched.
Dorothy L. Sayers (2013). “The Lord Peter Wimsey Mysteries: Whose Body?, Clouds of Witness, and Unnatural Death”, p.187, Open Road Media