Why would a guy always check up on me asking how im doing even years later?

This guy i dated literally when I was 14-15. Even after we stopped talking (he ended it) we would always bump into eachother throughout the years like at parties and stuff. And he would call me a lot randomly. One time I remember his friend called me saying he was locked in the bathroom talking about me and that I should call him. I never did. Years later I ended up having a baby and then he had a baby with someone else as well. But even now he checks up on me and we get updates on eachother. He likes all my pictures. I live in a different state as well? Why do guys do this? It's been 8 years

Why would a guy always check up on me asking how im doing even years later?
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