Some birds aren't meant to be caged

"Sometimes it makes me sad, though, Andy being gone. I have to remind myself that some birds aren't meant to be caged. Their feathers are just too bright and when they fly away, the part of you that knows it was a sin to lock them up does rejoice, but still, the place you live in is that much more drab and empty that they're gone. I guess I just miss my friend." - Red, after his friend Andy escapes from prison (in Shawshank Redemption)

It has happened before. And it will happen again. You kind of get used to it. And yet every time it happens, you feel like you lost a little part of your life... That little part which was made special by the presence of that person.

It always happens, especially in the IT sector, where people move around from company to company like loose leaves in the breeze... Settle a while here, then fly around and settle a while there and so on... You work with someone, you form a bond with them. Some bonds are temporary. Some are special. You move on from being colleagues to being friends. You share more than just work - food, jokes, insults, experiences, life... As time passes, you begin to rely on their presence. You get used to having them around. But then, one day, they drop the bomb... They have put the papers. And you only have a few days left to spend with them...

So when these special colleagues leave the company, you are lost for a while. There is a vacuum they leave behind. And however much you seek to fill it, you just cannot. Of course it is the law of nature that vacuum cannot exist for long. Something comes along to fill it up. Life goes on. And you learn to move on with it. After a while, you have adjusted to their absence. 

Of course, there are get-togethers and picnics and such with these "ex"-colleague friends. But now they have a different schedule and you have a different one. Soon you drift apart, and the occasion of your paths crossing become very rare indeed.

But for a while there, in between them leaving and you getting adjusted to their absence, the vacuum always makes its presence felt. And that's when you miss them most.