Thought I realized this a long time ago but I'm 33 and a friend of 15 years recently blindsided me with how little he actually valued the friendship. Been thinking about this exact topic a lot since then.
I think most relationships are based around utility and a common goal. Whether they're a training partner, you both snowboard, have the same politics, are drinking buddies, coworkers, etc., you need to be in alignment on something and get something out of one another that others can't necessarily offer. You obviously have to enjoy each other's company as well, but I see those two things as foundational.
In the case of my previous friend and I, we were initially training partners who liked similar obscure music. That alone kept us tight for years. Then I got fucked up on drugs and he seemed to want to take on the role of the older mentor type who gives unsolicited advice, and he got real comfortable doing so. It was fine for a time, but then I turned my life around and I have now surpassed him by virtually every metric imaginable.
He kept coming with the advice though and I tolerated it for years until I hit my limit, and the subsequent things he said after I called him out on it made me realize that the entire friendship had been sustained solely on him making himself feel better about his own life by telling me things he thought I needed to hear. All this time, I thought he was an old friend who was just misguided but sincerely wanted what was best for me and didn't realize I wasn't the same dude I used to be anymore. Turned out though that I was his refuge. He'd feel bad about himself or how place in life, then come ask how something was going with me, tell me what he thought I should do, act like he was doing me a favor and walk away feeling good about himself.
That incident is making me look at a lot of relationships differently now, and analyze why some past friendships fell apart and others didn't. People are constantly changing and all kinds of resentment can build when someone levels up or even makes a lateral move in life and the other can't adjust to it. If there's no utility or common goal anymore, then you're just two people with a shared history. As long as those things remain intact though, the friendship is largely what you make it. The second I called my friend out on his shitty unwanted advice, told him to stop giving it and asked him to put the mirror up to himself rather than me, I had no utility to him anymore.
Other people who were acquaintances have become close friends though and I have great people in my life now, so I don't know how fair it is to think negatively about most of my friends from over the years. Virtually everyone I was close with in the past forgave me for my years as a shithead and support me now that I'm doing well. I think the lesson I really take away is that not everyone is who they appear to be, friends or otherwise. People have supported me that I never would've expected and people have turned their backs on me that I never would've expected. People will surprise you. They lie to themselves and they don't honestly know what they want or are getting out of the relationship a lot of the time, so I can't even say it's intentional or nefarious. People are just flawed and wrapped up in themselves.
That only becomes more true the older you get, as people become increasingly stubborn, set in their ways and emotionally invested in the lies they tell themselves. The older you are, the harder it is to accept that you may be wrong about something and aren't being honest with yourself. I was forced to do all of that when I got clean, because I'd be dead if I hadn't. Most people are never forced to truly take an honest look at themselves, so they just go through life using people until they aren't getting anything out of them anymore and blaming everyone else for their own shortcomings.
