I’ve found through my work that people often treat the two favored “options” for closure - either getting it from/with them or giving it to yourself - as dichotomous, without overlap. And it’s not necessarily untrue since, sure, they can be for some folks. But even then they share a same axis point, and when it’s a disconnection of any kind between two individuals - partners, friends, loved ones, children and parents - and it is perceived to be permanent or negative, that point is the person (you/me/I).
We can give ourselves the “closure they never gave us” in the same (genuine, humble) way the parents of our friends were proud of us, too; it’s an almost perfect circle. And in recognizing the façade of a dichotomous experience, and reflecting deeper into the absence of words/explanations/excuses/messy fights/etc. we can permit ourselves some clarity.
Figuring out exactly what you didn’t get from them gives you the extraordinary opportunity to grieve exactly that: what you didn’t get. And then - because it’s all neatly conscious and confronted - it doesn’t linger as an unanswered almost in the background noise of life, of relationships with other people.
And it’s also extremely difficult and, often, a chronically aching experience. You can still hurt - for a long time - and you can still have bad days because of that one moment in your timeline. Because you are a human and because of course you do!!! Abandonment in any form is an inherent wound; a permanent “you weren’t good enough” that is never ever explained; an un-captioned nature scene. And this is all just how it goes, realistically, in relation to other people.
You can absolutely need to both move on and still feel sad about things that happened. Let it suck, and honor it in moments that you can.