do your grudges make sense?

Sometimes, characters in shows I watch get upset or riled up over events far in the past. I'm trying to decide if this is realistic or not.

One classic example is the revenge plot, where a character holds a grudge against the people that did them an injustice. For example, in Itaewon Class, Park Saeroyi is driven by revenge for his father's death most of the show, over a period of years.

Another example is "harsh words", where harsh words from the past are resurfaced far after they were spoken. A classic example might be a married couple where the wife brings up some harsh words the husband said years earlier in a present-day argument. A kdrama example for me is when Go Ae-shin in Mr. Sunshine holds a grudge against Gu Dong-mae years later for harsh words he said to her when they were kids.

On the one hand, people can build up an event and its emotional significance in their head, and let it bother them far longer than necessary. I remember a time when I got upset once as a kid, and I cried for several hours, which really was overblown for the trigger in question.

And people are pretty bad at updating their emotions on a person or event. I had this friend who did me wrong, like seven years ago. He suddenly re-appeared in my life and I didn't want to hang out, because of this grudge. But I realize those emotions are outdated. People can have a lot of character development in seven years. Yet my mind was like, screw this guy.

But on the other hand, emotions really do dull over a long period of time. In my own life, I had this big breakup when I was 18, that I never thought I would get over. Like the emotions were insane. But over time, those emotions actually dulled. (Matthew Walker thinks sleep in specific is what dulls your emotions over time, making sleep a kind of therapy.)

All this said, overall I would prefer characters that had motivations whose triggers lie in recent events, not events from the distant past. Sometimes it's justifiable - not all characters are super mindful and they can self-talk themselves into grudges. But writers should avoid having too many of these characters.

On the personal side - I don't want to develop grudges. I want to let go of my previous reactions to events and people, and just live in the present.