If you truly feel guilt for actions, instead of some made up bullshit religious people claim, it doesn't go away right away, and any trigger brings it back. Sure, your catholic confessor or baptism confessions might get you crowd or perceived divine forgiveness, but forgiveness for one's sins against others is ALWAYS internal.
Even if your victims are alive and forgive you, even if you pay them back for thefts, even if you MAKE restitution to your victims and they forgive you, in the end, YOU have to forgive YOU. This is how guilt goes away, you acknowledge what you did wrong. You try to atone. And you try to heal and get over it. Not everyone succeeds, not everyone changes successfully, not everyone gets over it.
This is how churches and governments have cashed in for millennia on guilt THEY created for things which no sane man should feel guilty about.