If it comes up or is relevant to a current discussion, I don’t hate talking about past relationships, but I’m not terribly sentimental and don’t talk about the past unprompted.
I’ve read that women truly move on from past relationships but men never do, we just deal with carrying it and no one wants to keep rehashing a past they never move on from. I don’t know what the metric for that is but I’ve never seen a woman so utterly destroyed after a failed relationship the way I’ve seen several men. There’s the whole support issue, sure, but even when a guy does have a great support group, they seem more affected by it, longer. That’s just my experience though.