Today I saw a quote that said:

"It's amazing when two strangers become best friends, and sad when two best friends become strangers."

I've kind of had both of those things happen recently, so I relate.

You know, it's one thing when time and distance and life experience slowly draw you apart...and even then, when circumstances are right, you can come back into each other's lives and pick up right where you left off. But when it's just hurt feelings, and miscommunication, and bitterness, and anger, there is no painless way to drift apart.

Even when you know it's for the best, for both of you, it's still sad.