Have you ever been in a situation/disagreement, only to realize that something absolutely trivial is scratching away at the foundation of the relationship?

It's happened numerous times with people who were once friends, but over time were reduced to nothing more than familiar faces and shared history. It's not pleasant as it forces me to question the validity of the friendship in the first place.

I suppose some might consider it sad, as do I.. that many of those people were befriended out of convenience. I find it much more unsettling because at one time my friends were closer than family, they were so important and valued. And now.. with a few exceptions, nothing more than memories, and I don't have any desire to try and make it more.

Perhaps I'm isolating myself, but the question remains.. why?