Most Helpful Guy
You may not think you have feelings for him, but a part of you does. You remember how much fun you two had together. You miss being close to someone like you were with him, and you want the intimacy. There isn't really a why here. It is what it is. Every breakup is different. You taking a long time to move past this is perfectly normal. Four years is a long time after all. Maybe it's because you don't have closure? Just a guess. It seems that the biggest reasons people have a hard time moving on are that, they still have feelings, can't let go, or don't have closure. If it's possible for you to do so, I would see about meeting him and getting that. It would help a lot. Take all the time you need, you're doing fine :)
Most Helpful Girl
LISTEN UP because this has been working SUUUPER well for me. I was talking to my best friend about how I struggle to stop liking a guy, and she gave me the best tip ever.
It's all about conditioning. You have to actively do it yourself and condition yourself out of it on purpose.
So every single time you think about him, remember something painful/hurtful he did. Any time you think a positive about him IMMEDIATELY think a negative, and instead of indulging in the positive feeling, think about how he hurt you and how he wasn't so great. Every single time.
The more you do this, you will condition your brain that when you think about him you don't think good of him. Trust me it really REALLY helped me with getting over my feelings. I've been doing this a few days now, I'm not completely over it because I'm still holding on a little bit but this mental exercise has helped TONS.