Why do I still think about my high school crush?

Anonymous
I had a pretty big crush on a guy when I was in high school/ early college. We went out off and on and went to prom together, but we were both so incredibly awkward that we could never take the next step and actually start a relationship. He eventually married someone else and I've since moved away and am in a long term relationship. He recently went through a divorce and has since added me back on all social media (he had originally deleted me when he was dating his ex wife.) I haven't spoken to him, but he has been liking some of my pictures and keeps showing up in my news feed. It's been years, but I feel like the old feelings I had towards him a resurfacing which just doesn't make any sense to me. It probably doesn't help that my current relationship has been VERY rocky this past year. Has anyone else ever experienced old feelings coming to the surface like this? I can't figure out if it's just a result of concerns I have in my current relationship, or if I never really got over him?
Why do I still think about my high school crush?
3 Opinion