just two stories to hopefully help you. tldr is time and self-improvement/self-care.
first rough break up. they weren't in my life but always in my mind. that sort of thing. even with new relationships.
6 years went by. i grew a lot. marx, chomsky, lenin, bakunin, pannekoek, etc.
randomly at a house party they were at. a group of us were sitting talking everything going on in the world at the time, local election, etc. they kept interrupting the conversation with their friend to talk about shallow boring nonsense.
needless to say i realized they were... not special for me anymore and frankly just fucking lame.
second hard break up i kept them in my life as a friend. big mistake, whatever. honestly they were just using me for company until soemthjing else better came along. whatever. i was at a music festival with them and the festival was fucking wild and fun but they were so pissy the entire time. i was like, "wow this person actually sucks holy shit."