Who do you think about?

Do any of you ever spend time thinking about someone who was randomly in your life for a brief period of time? I do. I was working one summer at an internship and I met this guy on my team. He was always pretty distant, but we got to know each other a bit. I always knew there was more to get to know, but time passed and we never truly became friends. I think about him every now and then. I wonder how he is doing. Not in a romantic way, but I just wonder if we could have been friends. Sometimes I wonder if I should reach out and say hello. Is there anyone in your life who you give brain time to? If so let me know. I would love to hear.