That permanent sort of thing that people casually refer to as "friendship"– two views

“I have often noticed that we are inclined to endow our friends with the stability of type that literary characters acquire in the reader's mind. No matter how many times we reopen 'King Lear,' never shall we find the good king banging his tankard in high revelry, all woes forgotten, at a jolly reunion with all three daughters and their lapdogs. Never will Emma rally, revived by the sympathetic salts in Flaubert's father's timely tear. Whatever evolution this or that popular character has gone through between the book covers, his fate is fixed in our minds, and, similarly, we expect our friends to follow this or that logical and conventional pattern we have fixed for them. Thus X will never compose the immortal music that would clash with the second-rate symphonies he has accustomed us to. Y will never commit murder. Under no circumstances can Z ever betray us. We have it all arranged in our minds, and the less often we see a particular person, the more satisfying it is to check how obediently he conforms to our notion of him every time we hear of him. Any deviation in the fates we have ordained would strike us as not only anomalous but unethical. We could prefer not to have known at all our neighbor, the retired hot-dog stand operator, if it turns out he has just produced the greatest book of poetry his age has seen.”
― Vladimir Nabokov, Lolita

“All along, Patty had been unaware that time is as adhesive as love, and that the more time you spend with someone the greater the likelihood of finding yourself with a permanent sort of thing to deal with that people casually refer to as "friendship," as if that were the end of the matter, when the truth is that even if "your friend" does something annoying, or if you and "your friend" decided that you hate each other, or if "your friend" moves away and you lose each other's address, you still have a friendship, and although it can change shape, look different in different lights, become an embarrassment or an encumbrance or a sorrow, it can't simply cease to have existed, no matter how far into the past it sinks, so attempts to disavow or destroy it will not merely constitute betrayals of friendship but, more practically, are bound to be fruitless, causing damage only to the humans involved rather than to that gummy jungle (friendship) in which those humans have entrapped themselves, so if sometime in the future you're not going to want to have been a particular person's friend, or if you're not going to want to have had that particular friendship you and that person can make with one another, then don't be friends with that person at all, don't talk to that person, don't go anywhere near that person, because as soon as you start to see something from that person's point of view (which, inevitably, will be as soon as you stand next to that person) common ground is sure to slide under your feet.”
― Deborah Eisenberg, The Stories (So Far) of Deborah Eisenberg