Is it normal that i miss this person?

I'm in college at the moment, however, back in high school there was this professor who never actually taught me but we always seemed to talk on a daily basis (on school campus whenever we bumped into each other. Got to meet him during an ECA at school no biggie) and joke and stuff. Very casual. At one point it got slightly weird because It seemed like he'd always end up where I was (i.e. library, labs). We usually just joked about stuff, talked about life in general and how the students he taught (much younger 13-15yr olds, I was 19 at the time, final year) got on his nerves and if I needed help with any of my courses etc. Nothing inappropriate. Anyway, is it weird that I miss him? After I left we kind of lost contact but I have siblings who still attend the same high school, but given that I study abroad I haven't actually found the time to visit.

I got to meet this professor during my final year so I only knew him for a year. I'm not some psycho who gets overly attached to random people but he wasn't like that with everyone. My friends used to always tell me it was a bit odd how much time and effort he dedicated to just sitting at our table and having all his attention on me but I always though he was endearing, just a very down to earth kind of guy. He was around 15 years older than me incase you're wondering and I've been out of high school for a year and a half now.

Is this normal??