People I'm no longer friends with still appearing in my life.

Kind of hard to exactly describe what I'm going through, but I'll give it a go. For a multitude of reasons I've lost contact or fallen out with various groups of friends over the years (my fault or theirs, it doesn't matter anymore), but I still see them crop up on social media and the like via mutual friends that we still have. What makes this even more frustrating and annoying to me, is that many of these people only knew each other through me in the first place, yet I'm the one who has been excluded! I know that's a selfish way of thinking, but I can't help it. It's also frustrating in the sense that all of my current friendship groups overlap and connect in ways that always leads back to these types of people, making it impossible to escape from. It's like I can still feel them taunting and laughing at me, despite having no contact with them. I would love to hear from anyone who's been in a position similar to mine, particularly if you can help me deal with it. I imagine most advice would be to simply avoid and ignore it, but I can't help but feel that doesn't really work in the long time. Deleting social media isn't really an option and this kind of thing happens in real life from time to time as well. Can anyone help?