Do you ever just not like someone? For no good reason?
I have this problem with some people. I have no idea what it is that causes it, but there are some people that I just can't stand. They've never done anything to me. They don't treat me badly. My friends like them just fine. I couldn't think of good enough reason not to accept a friend request from them. And yet, pretty much from the second I meet them, I feel an instant, visceral dislike. Maybe it's just bad chemistry, maybe it's the alignment of the stars, or maybe I'm just crazy, but every time such individuals are around, I end up locked in an epic battle with myself. On the one hand, I feel like a cat who's been rubbed the wrong way. All my emotional fur is standing on end, crackling with static-y hatred. On the other hand, society frowns on humans taking random swipes at people just because you feel prickly. So, I wind up caught somewhere between displaying active dislike and active friendliness. This look is also known as "resentful apathy." I call this special attitude the Margot Tenenbaum:

Needless to say, this completely fails to conceal my rampant dislike. I end up feeling like a huge bitch, because I can't feign interest in someone I find so completely distasteful, in addition to feeling the aforementioned static-y hatred.
Through intense reflection (generally done while staring at a hated acquaintance with the closest thing to a blank look I can engineer), I've deduced that there are three major categories of these auto-hated people:
1) Reminders
These are the people that, through no fault of their own, probably remind me of someone else who I disliked, usually for good reason. I've had a couple of classmates who instantly remind me of H, my ex-best friend, and I can never really like them once I figure out why they seem familiar. This also applies to people who remind me of myself at my most irritating ages. There's nothing worse than being forced to confront both an unpleasant person and a reminder that you used to be just like that person.
2) Bitches
I'm sorry, okay, but some people don't deserve for me to like them. With these, it's really a chicken or egg kind of thing. They're rude to me, I'm rude to them, they're rude to me, and so on and so on...but is it because they know I don't like them? Or do I not like them because they were bitchy because they didn't like me? Fortunately, this group is the least guilt-inducing, because generally at least some of my friends also aren't so fond of them.
3) Puppy people
Sadly, this is by far the largest group, and yet also the group that I don't have a logical explanation for. These people have done nothing to me. They're not rude. They don't remind me of anyone I hate. Regardless, they bug the crap out of me. I call them puppy people because they act just like puppies - eager to please, a little slow, and blissfully unaware of any dislike directed at them. The Margot Tenenbaum goes right over their over-friendly heads. Some are too loud, some are too quiet. Some laugh too much, some are too self-conscious. Most are really bad at reading social cues. And they all seem to really, really like me. I can't be mean to them to make them go away. I would get this:

And so I sit there, thinking, "Go away. Goawaygoawaygoaway. Go away. Go away. Don't you see the Margot? WHY WON'T YOU LEAVE ME ALONE I HATE YOU."
Once they finally slink off, I'm left wondering what the hell just happened in my brain.