Adults just don't understand. We want the kids to live in harmony with one another. I approach things with a less Disney-esque perspective. Most of the time, there are few friends and intruders are a plenty. I don't care if you like everybody in your class; but I do care that you treat each other with respect.
If you really want to understand what our kids go through all day, imagine being in traffic for 8 hours a day. Most other drivers are cool. I mean, they're all in your way and it would be great if they weren't there.
There are a few who do awesome things. They let you in their lane. They let you merge onto the highway. They shine their lights at you to let you know that yours are off. They'll let you know when a speed trap is ahead. But those are few and far between.
More common is the *$%&*# drivers. They cut you off. They put you in danger. They make you fear for the lives of your family. They are rude. They're inconsiderate. They make your whole body tense. You have no kind words for them. You talk about their idiocy for weeks every time you encounter them. There's little forgiveness. I remember cars from 10 years ago... especially the *$%&*# driver that ran me off the highway when I was 18 (over 20 years ago).
I also remember the kids in school who behaved similarly. Being in a school is like being in traffic, stuck with a bunch of people you didn't choose to spend your time with and you have no choice but to be there.
And we can't forget how perceptive kids are. They're "stuck in traffic" with the same cluster of people. They recognize trends and patterns. We, as adults, might wonder why they're blowing up over something that seems so small. But we haven't always seen everything that led to that conclusion. When you're driving and you recognize a driver that's aggressive and reckless, even a casual mistake looks like an intentional, aggressive move.
This is also an important thing for the kids to understand. People pick up on patterns. If you're regularly starting problems with others then when you genuinely make a mistake, you won't be given the benefit of the doubt. And it isn't limited to just the person you created a problem with. Every action you make is being watched. You cut somebody off, you're bothering more than just the person you cut off. And this affects how people think about you and treat you.
We can't help kids process through their problems without understanding the context. And really, it's tough to relate because there are so few places we go as adults that are like school for kids. Sitting in traffic always reminds me what my students go through on a daily basis... for 8 hours straight. Helps me remember to cut them some slack when they seem like they're on edge. It also helps me remember to look for the underlying patterns that lead to the interpersonal problems I see.
Recommended Reading
The Ultimate Guide to Teaching Four Square - Using mini-games to teach all the skills and rules
Ultimate Kickball - Kickball without all the problems that come with Kickball. Also insanely fun.
The Ultimate Sub Plan - A fool proof plan for emergency sub days
A Better Way to Make Teams - Give children the power of choice