In university, I made a few friends who went to different international schools growing up. Their parents were diplomats or executives who moved cities/countries every couple of years, and they'd switch schools to go with them. They were charismatic and personable, and quick to make friends.

But at the same time, after our natural relationship ran its course (due to graduations or leaving a student team), it felt like they disappeared. My relationship with them wouldn't linger like with other friends (even if weakened).

Another friend of mine directly described this view that "friendships have a time and place" in life. I thought about that perspective and didn't fully agree, but it still taught me that it's perfectly possible and even healthy to make friends quickly even if circumstances are temporary.

My view is that even if you become good friends with someone (at work or elsewhere) and they leave, you still end up with a network of friends across the country in different workplaces. Even when the nature of the friendship changes, you can still catch up with many of your old friends on occasion (like around the holidays).

And even if relationships completely fade, I believe that genuine relationships will always be a nice experience.