From a book by Judith Viorst, Necessary Losses, Chapter 12, Friendships.
People in the US use the word "friend" very loosely, just like the word "love."
Her categories are not written in stone, but they do illustrate how friendships differ, and in my case, why some seemingly melt away without any reason.
Good friendships don't "just happen" any more than good marriages.
What passes for friendship at the KH many times is a mutual "using" of each other. When you are no longer useful, they move on to the next usee.
So if you have a good friend, Larry, hang on and nurture that relationship and give at least as much as you get.
I still think changing location and/or congregation sifts out your real friends. When it is no longer convenient, most will fade away.