In the general scheme of things (life), that's what always happens from one's individual point of view. People enter one's life and, after some time, they leave. Even if that person is the one leaving, the same is true from the point of view of someone else. Also, things in life come in groups, never singled out. A friend of mine back in school developed this theory by which you either have no girls interested in you, or a multitude going after you, but rarely something in between (keep in mind that this was high school, ok?). By taking this thought a bit further, we can speculate that the same applies in most things, such as friends, jobs, money etc. People usually make a reference to things coming in pairs or threes, but the chain doesn't have to stop there. It's sort of like the tide, which either brings water and new things ashore, or takes water and old things and sends them travelling to wherever it is things that are adrift go, until they land somewhere else again.
Why am I saying all this? Well, the tide is changing again from my perspective. I came to St Andrews and left people behind, so in a sense they were taken by the tide further away from me. I met new people here, made friends while the tide was high. But it is the time now that people are leaving, and I'm just standing on the shore watching them ride the waves towards new destinations. It has been happening for a while now, but it will peak within the next few months. It's not all bad.
It saddens me to see people leave, especially since knowing how bad I am at holding on to people that are not in my immediate surroundings, I somehow know that keeping in touch with them will be only a possibility (and not a certainty). People that I've learnt to rely on (and by that I mean anything from just having them around me, therefore relying on them for a sense of belonging and familiarity, to literally me depending on them) have been going away one way or another for some time now, but I'm not used to it yet. I hope I never will or, rather, I hope I won't have to. But as I said, it's not all bad.
People leaving are usually doing so in order to achieve something, to make things better for themselves, or to get away from things that aggravate them. It is a good thing for people to move on, as such is the human nature, to always reach up for more, to always struggle for what's better. People have always waited (and relied on) the high tied to begin new voyages and journeys, and people being left behind have always been saddened by that; they have also always been happy that someone was able to leave, that another part of their family/community is now venturing towards a better world. Parting is such a sweet sorrow, no?
I shall watch another high tide come and go. With every tide that comes, I find myself looking less and less for new things that have drifted ashore, but I have always watched the high tide go. And when this cycle is over, I will not be sad. After all, I'm only waiting for one of those high tides myself...