What is guilt? In which situations do you feel guilt? When do you feel guilt?
When an bad action occurs that we feel responsible for?
There’s a desire to undo, or compensate, for the action: to make up for it.
When you feel guilty, you feel in debt. But rather than remorse or apology which occupies a psychological debt, guilt is a physical debt.
Is guilt selfish? Yes, but it’s less selfish than not being sorry. Usually when people don’t feel guilty they’re looked at as evil.
I believe people often conflate being sorry and being apologetic. Can you be sorry without wanting to apologize? I believe so.