Best friend or only friend?

Being almost half way to 50 has taught me various things about life. One of them is who is your real friend? There is this quote saying that when you were in Elementary-high school you had many people you considered best friends. But then as you grow older, only few left. This quote is a truth.

I know we grow up. I know we chose different path of life. I know nothing last forever. But it is just sad thinking about all good days we used to share but now we cant even hold a decent conversations. It is sad when you realized you cant even tell your best friend about how you feel, for you start to think they are not interested in what happens in your life anymore. Or worse because you think they dont care anymore. Or because they dont even want to share whats going on in their life, making you realize that you are not as important as you used to be. Thus, at the end of the day, I wonder what are they now? are they still my best friends or just a friend? I also wonder what I am to them now? I wonder about how they think of me? Because in the last few months I have realized that some of them dont think of me as important as how I think of them.

In which category our friendship belongs to now?