Many years ago, when I first began teaching, I used an essay by a writer whose name I cannot recall at this time. The essay was about friends--childhood, work, school, hobby etc. Some friends you see once in a while and yet when you get together the talk and the affection seems to be the same as when you hung out together regularly.
Their are casual friends, friends for when troubles come, party friends etc.
When there is a sudden unexpected end to communications between friends of long standing the pain is as deep as when someone in the family passes away. I could be paranoid and say I'm to blame for the loss of friends I once considered close. However, I see that humans change and the things that bound us in the past no longer apply. So today I'm saying goodbye to the idea of another friendship in hopes that I can move on and acquire a few more to fill the void.
Knowing me, I probably will and hopefully I will learn more about friendship in future endeavors.