The most sensible thing to do if you miss someone would be to get in touch. Call, text, write. There just has to be a way of getting the other person to know how these you feel.

However, if there's no means to reach the person, or if it's counter-intuitive, you might a well get to doing things that will help you keep your mind off the thought of the person. Go out and catch some fun, take up a new hobby, just do things that would get your mind busy.

It's not a bad thing to miss someone though. These things are part of being human. It's bound to happen.

Very recently, I left a place where I'd spent the last eleven months of my life. I still miss people there from time to time and try to get across to them. I think it's the wise thing to do.