It's mostly dumb because of how small these pet peeves are. It isn't something like "you always flake when we make plans" or "you can never get along with any of my other friends". No, it will be something as dumb as "I don't like how laugh" or "It's irritating how you always turn down my offer to help" or "you have a habit of cutting me off when I'm telling a story". It isn't fair to dislike trivial personality quirks, but I get stuck on them. If a friendship goes on long enough, I start associating their existence with that thing I don't like.
This usually takes about a year for me to pick it out, but my disdain for it only grows. It's different if I don't see the person often or if I physically have no choice in the friendship (like family friends). In rare cases, too, they will change and I'll be able to enjoy their company once more.
I think this trait of mine has been a serious deterrent in something that everybody finds eventually, though.
I've never "clicked" with anyone ever. I've never had a best friend where we always understood each other. I hear about the people that have been friends for over a decade, and I literally cannot fathom that kind of relationship. Like, I'm close to my brothers, but they're my brothers, it's different. I can't imagine somebody I am so close to and sympathize with so vividly that it is second nature to be talking to or hanging around with them.
The best friends that I've had in the past (with these friendships usually lasting around three to four years) have been due to either proximity of sharing classes together or common interests in liking the same video games or activities. When either of those things change everything falls apart. The only person I regularly speak to that I've known since middle school is Sain, who I rarely see, and I can only think of one other person that is still on my phone's contact list, and while we can have a genuine, long conversation, we don't talk much anymore.
Basically, ever since I evolved from 'child', my best friends have always been my brothers, because we always like the same games and the same books. We're practically one person with slightly varying models. Devon is good at computers, Nathan is good at cars and guns, Ryan is good at visual art and general designs, and I am good at fantasy creation and writing I guess. When we form a guild or clan in a video game, most often our powers combined makes C4. Not the cleverest of names, but I like it.
The funny thing is, I've picked apart what I don't like about them, too. But it's different because they're family. I think I've gotten better at shunning that distasteful quality of mine, but it's still there. Maybe one day I'll be able to get rid of it entirely.