That guy that you "hate" would probably be your BFF in a different circumstance

Something that took me a long time to understand was that judging people and allowing them to spark a reaction in you is futile.  Not only does it get you no where productive, but in different circumstances, you'd probably actually like the person you've put on your judging platform.

I learned this in college through rowing.  My target was gregarious, loud, confident, but more importantly, holding the winner's cup that I had been expecting to collect all year long.  In short, he was me, but a better version of me.  I "hated" him for it.  A spit on the ground in front of you, western movie kind of disdain that I felt was totally justified.

Fast forward two years.  We're both still rowing, but now we're on the same team.  I bring the same attitude in and I don't talk to him, I don't look at him, I don't laugh at his jokes (even though they're actually quite funny).  Weeks go by and he seems impervious to my coldness, offering up compliments and congratulations on jobs well done, workouts crushed, beers chugged.  Another three months go by and this guy is one of my closest friends.  We carpool together, run errands together, row together... an undeniable bromance.

What did I learn from this?  If you're competing in a sport, working for the same company, in a rival fraternal organization, whatever the context of this arch nemesis, chances are you have a lot more in common than you're willing to acknowledge.

This reality is always hiding in the background, so a more productive focus would be on the task at hand, not your feelings and perceived justification for these feelings.  Not only will you be a more likable person by minimizing the list of folks that you "hate," but your stress levels will be lower, making you a healthier person.  I can go into the science behind that if you want, but let's just cut to the chase; if you "hate" someone and it's for reasons other than true moral deviance or wrongdoing, you're probably carbon copies of each other and its simply the reflection that's making you uncomfortable.