Student Exchange Programs

There was this guy I was dating a year ago. He was an exchange student and we both knew that by the end of the year we would have to say goodbye and move on as he lives overseas and I live in North America. We said goodbye when the school year ended and continued to talk over email for the whole summer. After that I guess we both realized we were just making it harder for ourselves than it needed to be and ended all communication. I guess what makes it hard to get over is that neither of us ever wanted it to end and we never really had a “breakup” in the traditional sense. I may actually be moving to his side of the world in a couple years for grad school and what I’m wondering is do you think it’s unrealistic of me to think there may be a possibility of us getting back together? I know he has not been seeing anyone since we were together a year ago. Also, should I contact him just to say hello or is that a bad idea? And lastly, I have family in the city he lives in and was thinking of going over there to visit them and spend time in one of my favourite cities in the world, would it be unrealistic of me to think we may spend time together when I am there?