It's hard to forgive someone after they've done something. Whether they ate your chips, used your stuff or ruined your life, we tend to not forgive. We hold grudges and resent them. Here, we're just ruining our own mental health by going after someone who has already done something. What happened has happened. There's nothing that can be done now. Live, and let live.
Let me give you an example. Let's go to a classroom. A student makes a mistake, the teacher gets angry at him and scolds him. The student makes the same mistake again. The teacher gets angry again and scolds him. This went on for a while, until the teacher thought of something, why not change the attitude towards him? The next time the student made that mistake, the teacher didn't become angry, instead, calmly explained what he did wrong and gave him tips on how to solve it. The student started improving and overcame his mistake! This story I gave you is real.
So what can we do? If someone does something bad, we have all rights to be angry. But we shouldn't just be angry at them forever. We should slowly start forgiving them, stop resenting them. This greatly helps our own mind, and we can give it the calm it deserves. We should heal instead of hating.
Forgiveness is magic. If we forgive someone who has been bad to us, they'll just have a change of heart. They'll start to feel bad about themselves for being rude. They might become nicer and closer.
We can never know what someone is going through. They might have done something when they were not at their best, we should learn to forgive, as it could save lives.
This can also be vice versa, someone might have done something to us when we were not at our best. We'll not be able to immediately forgive them, but over time, we should. Because at the end of the day, it's better for our own mental health.