Time to connect

I have a sense of lost community. Maybe it is a fable, a place where you know people, and they know you. I imagine this sense of community takes time to coalesce. When I was a child, I felt very connected to the people and places I spent time near.   Every time I move, it takes many hours of casual interactions - talking about weather with neighbors, people working in stores, public officials - to reestablish a natural connection to the people around me. I'm terrible with names and it takes me many times of hearing one to recall it. I am also not particularly outgoing and don't introduce myself to others. It takes a lot of energy to make friends and it is painful to loose them. It seems that around five years in one place, I start to feel like people know me and I know them. Since childhood, I only once lived in a place for that long. There are natural communities formed around schools - spending that much time with others creates life-unique connections. When I think about where I'm from and what schools I attended, I still feel connected to those places and the people I spent time there with.   Increasing housing costs make it harder and harder to stay in one place for many years. Many friends and family move regularly, or live with their parents.  

How have my connections to communities changed because of displacement? Does it discourage connections based on common location and encourage more connections to others via digital means? Is this a new situation, or were there times in the past, like the industrial revolution, when displacement was high? How did people forge communities then?