Thinking about Ex?

Is it normal to think about your ex? I have no desire to reach out to him but I do kind of wonder sometimes how he is and if he has ever thought about me. Things ended amicably as we weren’t good together in a relationship and probably would have been better as friends. We live in different countries and have both moved on with our lives. I just don’t know if it makes me a horrible person that he sometimes crosses my mind.