a quote from random blog browsing:

"The saddest thing about friendship is that it can die. It doesn't come with a lifelong guarantee. Distance is one killer. Unless you are diligent in keeping in touch with a friend, being far away can drive a wedge in your relationship. Changes in circumstance is another. It has been said that a friend in power is a friend lost, and I have found this to be true. When a friend moves up in life, he will become too busy for you, while you don't want to risk rejection by trying to keep in contact with him. Marriages have also caused friendships to fade as your spouse might not take to your friends. Then there are friendships that die because they have simply run their course."