Why is it so hard to be a good person?

Being kind is a human thing, that said, anyone can be kind. Even though sometimes some people will just pull you out from the light and unleash that inner bitch in you. Still, you have to be kind. My aunt once told me a few years ago that keeping anger for someone is unhealthy. BUT GODDAMNIT, some people will just drain out every drop of kindness in you. It's hard because it's confusing to deal with it. If you call out someone's bullshit, people will see you as the wrong one, if you don't, automatically, they won't stop with their BULLshizz. You'll end up not doing anything about it, but then, someone said, the problem with this world is that the righteous keep quiet. So, what now?