I think we'd do well to reframe the definitions of guilt and remorse to improve any relationship. I do not think that these words should be synonymous. I believe, at the best of times, we know exactly the qualities that comprise what we consider to be a good person.
Any time we deviate in our actions from the framework we have in our mind, we understand that those actions make us feel poorly. Simply put: we understand that we have committed a wrong, thus causing guilt. Guilt is a self-centered feeling; it is the scrutinizing introspection of actions. There is nothing wrong with guilt as an emotion; humans are inherently flawed creatures and are prone to making mistakes.
But remorse? Remorse requires empathy for another person. It requires us to center the victim of harm at the heart of the conversation, which is where they belong - at the heart of it, at the heart of our compassion for having caused them harm. Remorse proves to be a more powerful harbinger of change. It brings us sorrow to our doorstep, to gently lay it at our feet - a testament of what we never want to do again, if we can help it.
Guilt only serves as a vortex dragging you to the bottom-most depths. It spins you out, flinging you further away than when you started; it sends you further away from achieving the clarity you need about the events that took place, the role you played, and it obfuscates the way forward.
Prolonged guilt at the expense of remorse is fucking selfish.