Life is full of phases. Easy segmentation comes in the form of school graduations and new jobs. These moments force us out of our houses and friend circles and introduce us to entirely new groups of people. Colleagues become friends, and fellow students drift away into Facebook birthday reminders. Some times they, or we, resurface a decade later, in a different town. Usually not. And when the new job ends we leave behind most of our colleagues, save for one or two we still see outside of any office, in circumstances far divorced from the workplace that first introduced us.

Life is fully of these changes, more for some people than for others. Depending on how often we move, how many jobs we have, and how many schools we attend the number of groups we’re part of varies. The kind of interactions, though, are stable. Out of each group there will be people we connect with, people we want to hold on to when the binding circumstance drifts away.

Living in upstate New York, at Vassar, and then in Tokyo and Shanghai, my groups are varied, distant, and rarely overlap. I’m lucky to have even one friend that shares multiple locations, let alone three. Most of my friends come from one of the many jobs, one of the many frisbee teams, one of the handful of cities. People I met while working at a delivery company in Shanghai, or a teaching job in Tokyo. Like most, I have friends from middle school, high school, or college. And now, on the west coast, I know people from a couple of jobs well enough to invite them over. At least one from each.

For those of us that move frequently, that have homes in different countries, friends in different cities, that’s a good place to start: one from each. Writing letters to Seth in Singapore last week I realized how special it is, to have him remember my apartment in Tokyo, to have him know my first apartment in Shanghai, and the grass of Vassar’s quad. There are several people who I can share each set of memories with, but only one who knows all three.

Standing last night in a yard in the Oakland hills with a friend from a job in the US, meeting his wife, brother, and father for the first time, I realized he’s one of a few, of very few, that I will stay connected with from those three years driving to Petaluma every day. There are others, scattered all over the globe, people I remember and will connect with when able. But few of them will invite me over, few will I meet up with in Shanghai late on a Saturday evening when all our work is done.

One is enough, sometimes. Given how much I like change, adding someone at each stop is a good pace. Sometimes I am lucky, and a frisbee team gives me a plethora. But it’s good to find someone from each part of life, to help with my memories, and to prove that we built something over all those days together.