It's a known fact that people in my industry lead very transient lives; this can be a good thing for some who are particularly intent on not forming any sustained relationships. Initially I was quite fond of this perk of the job as it were but over time I've found that I kind of want something a little more prolonged than a month or two. Out of necessity friendships grow very quickly on ships and its not uncommon to hear people refer to "ship years" being worth more than the equivalent "land years".
One thing I've done to adapt to people coming in and out of my life so frequently is to develop "layers" of friends as it were as levels of insulation. Most ship people, with fewer exceptions than I can count on one hand, don't really get to the inner layers.
This topic comes about, as you might have guessed, because someone I have grown rather fond of is leaving the ship on Sunday to transfer to another ship. It's not anything that I have any control over and it sucks but, to some extent, it's just how things go out here.