Have you ever just disliked someone for no reason? Perhaps the sound of their name just makes you feel like someone shoved a lemon into your mouth. Or maybe hearing about them doing anything automatically makes you hate that thing. Maybe, that person actually did do something to you somewhere along the way and you can never forget what they did, even though everyone else already has.
It's even worse when you seem to be the only person in the world who has a distaste for that certain person while everyone else thinks that they are God's gift to Earth. It makes you feel dirty and rotten on the inside, yet, you just can't get their bad taste out of your mouth.
You start to obsess over the fact that you don't like them and feel like you're crying wolf every single time you present new evidence that screams that that person isn't all sugar and spice. Yet, it seems like it falls on deaf ears.
I knew a girl once that was the perfect child to virtually everyone. She volunteered, loved church, loved little kids, and did her best in school. Everyone loved her for the good, bad, and ugly. And when things got ugly (and they sure as hell did) she still came out the other end smelling like roses and every other person makes excuses for why she wasn't the one in the wrong.
At some point along the way, I gave up. I stopped trying to make people see things the way I did. I let things simmer inside my stomach and try to find the good things about her, but slowly she would tick away at the fine mask that I put on. I felt so lost in hate that I was convinced I would never find the light again.
A friend, though, shined a light on things for me. Everyone knew what she did, but no one felt the need to step in and tell her otherwise, also no one could because that's just who she is. I felt a little lighter somehow about that, in knowing that she was who she was no matter how many times I pointed out the bad things she had been doing.
She was always going to be someone I didn't like and she would always continue to do things that would grind my gears if I let her, but that didn't mean she won. I stopped trying to make myself like her or agree with the things she was doing and I felt better. I realized that she could be whoever the hell she wanted to be and it was perfectly okay for me not to like who she was. The only thing I had to do was respect her and be civil with her, which, granted, is much easier said than done.
You have to let yourself be human. If someone really just ticks you off, don't spend precious time and energy trying to pinpoint exactly why they tick you off. Also, definitely don't let them get under your skin because, at the end of the day, no one will care how you perceive them and you're only wasting your own time trying to prove they aren't perfect. All you have to do is exist and let them exist, peacefully.