Why do I think everything revolves around me?!

There's a guy I met in university long time ago , which I liked and liking was mutual but another guy interfered and we didn't end up together. I was sitting in a bar yesterday and I just turned my head and saw him. He saw me too and positioned himself so that he can watch me. I felt uncomfortable, knowing what happened between us. But today, he's posting songs and his current location on Instagram stories whole day long. And he didn't post for weeks before that. Maybe I should go to that bar and say Hi