I'm looking for a concise way to describe this situation:
Person A compliments B's team at a competition. But B does not respond to this compliment gracefully, even though it means a lot to him. B senses that doing this has hurt A, but pride or shyness get in the way of him clearing the air with A about this for a while. When B works up what's needed to talk to A, unforeseen circumstances change B's plans and he loses touch with A. Years pass, but B continues to feel an urge to fix his mistake. B does not actively seek to fix it (aside from learning from it), but if the opportunity to do so presents itself he has told himself to take it.
One idiom I've considered is turning over a new leaf. But this phrase seems better for a personality overhaul than for repairing one mistake.
Is there a word/idiom/phrase (WIP) to describe a person who would leap if given the chance to correct a specific mistake he made?
Edit: I have received some great answers, but I've realized I have one more condition I'm looking for: I'd prefer a casual/conversational WIP. Thanks!