The only constant in life is change (Heraclitus).

Nothing lasts forever. The same applies to friendships. I have only 4 true friends. And even these friendship relationships are different now compared to what they were like before. It's not the same relationship that we used to have. We're still true friends, but our relationship is different than years ago. So, change is constant, from bad to worse, from good to better, from yes to no. Hard to come to terms with, but it's true.