Not all the time. But for a while.

Blame it on evolution. We are a herd animal and do not like to be alone.

Yes… but it is above average to appreciate those in our life right now.

Not all the time. It would be abnormal not to miss people we care about who are absent ever. If you miss someone or people all the time perhaps your life is empty? If I’m busy and engaged in my life I don’t find the time to dwell on those who aren’t with me so much. They pop in and out of my mind, sometimes fleetingly but enough to make my eyes water, and then they blend into the background again.

Our sights are not calibrated accurately?

^^I don’t need sights, i’m a crack shot at lobbing M&M’s at passers-by & I never miss.

I don’t miss people very often, but I’m more of a loner type person. What is the circumstances of missing someone that is bothering you?

Because our brains were shaped during the hunters and gathers period.