Relationships are fragile. What makes them even harder is when they break apart for good. Not only does each person have to forge a new identity on their own, but they also have to deal with the broken relationships between their ex-boyfriend/girlfriend and their cat.
If a cat loved your ex-boyfriend/girlfriend, how do you tell your cat that they’ll never see this other person again? Cats don’t understand human relationships and they can suffer from depression when they no longer see a favorite person any more.
Perhaps cats can help keep people together, or at the very least, cats might petition for visiting rights to see the people they liked even though their owner no longer likes that person any more. It’s enough to make you realize cats have an easier life than humans.