So one of my armchair interests is to what degree the modern "move to eight different cities for school, work and adventure" lifestyle is a historical anomaly, and how to maintain communities when half the residents are temporary.
Friendships, like community, requires proximity. If you live where you grew up, it is easy to maintain the friendships you made in highschool. If you move to a city to go to school there, then take a job there, it is easy to maintain friendships with your friends that do the same. Work friends are more easily maintained while you work together, or at least work nearby afterwards and frequent the same recreational venues in your free time.
If you move around a lot, jobs and cities, it takes quite the effort to maintain friendships.
Friendships, like community, requires proximity. If you live where you grew up, it is easy to maintain the friendships you made in highschool. If you move to a city to go to school there, then take a job there, it is easy to maintain friendships with your friends that do the same. Work friends are more easily maintained while you work together, or at least work nearby afterwards and frequent the same recreational venues in your free time.
If you move around a lot, jobs and cities, it takes quite the effort to maintain friendships.