Are we all growing out of our “forever friends?”

In the past few years, as I’ve established myself in my career and my “adult life”, I’ve found I am less aligned to the people I had considered my friends forever (mostly from undergrad). I want to caveat this post with these are not proximity problems. I’ve lived in different places than them since 2011, and we were all good about visiting each other. Are we all experiencing similar things? Is this just what happens in the mid-30s?! Should I have more grace and patience? Or is nostalgia not enough to hold people together?