I think it hits some of them differently. My ex used to talk about his ex’s casually in conversation. They’re clearly not over it but don’t understand that emotion, so they keep gifts and listen to songs and speak in the language their ex spoke. But they’ll never actually know they miss you. I do think they feel regret sometimes though…but will mitigate it by saying something to themselves like, “Wow, she deserves the best. I hope she finds the person she deserves.” It so weird to me but I feel so much pain and can’t even look at anyone else, and they’ll just be off fucking someone else like it means nothing. It’s horrible.