For me, it's a person I dated for almost 2 years. We were on and off a few times, and any time I tried to move on, I still was always thinking about them.

For context; the relationship (LDR) wasnt really anywhere near perfect. We were both awful to each other at times. Examples being me being possessive and over reactive a lot of the time, and them enabling and encouraging that behavior. There's also the matter of the fact that they ghosted me for I think about 6-8 months. This caused a downward spiral for my entire life.

Anyhow, we ended on probably the worst terms, both of us basically saying "fuck you" to each other. Months go by and I always thought of them, but moved on to a healthier relationship that I'm still in today. 2+ years and I've never been happier with someone but I did something I regretted.

I checked up on my ex on social media and tried to message them to apologize for everything that had happened. It didn't go over well. They nearly blew up on me and tried to make it sound like I had ruined their life. I didn't know what to say so I just let them keep going on about how I'm the worst. And then I just stopped talking to them and blocked them.

But even after that, I still think about them.