We're often warned, from our parents on forward, not to hold grudges against other people. It can diminish you, make you resentful, you know?
Sophie Hannah calls "nuh uh" on that. The prolific crime novelist finds virtue in harboring at least a little resentment, and she demonstrates in her non-fiction book How to Hold a Grudge: From Resentment to Contentment—The Power of Grudges to Transform Your Life.
In her telling, grudges can be good motivators. We get the lesson from this interview from 2019.