^ A similar lesson - the same happens as friends grow older. Kids are like puppies or kittens - not only are they not fully formed yet (the brain doesn't finish its growth until around age 25) but in youth they're super resilient and openminded and able to get along with anyone. I think its a survival strategy, making it more likely they'll be supported and liked by whoever needs to take care of them and making it hard to get mad at them. But by the time you're past college age you're really starting to get firmly set in who you are, and from there it only gets stronger. The things that cause total rifts between adults don't matter when you're kids on the playground.