What does the movie Batman: The Dark Knight tell us?

Don’t talk about benevolence, justice and morality like them, you are not one of them! No matter how hard you try, you won't be able to fit in. To them, you're just a freak like me. They need you now. When they don't want you anymore, they will squeeze you out later. Look at their moral code, their laws and regulations: it's just a bad joke. When there is danger, they reveal their true colors. Only when there is peace and prosperity can they live in peace with each other. I will prove to you that in times of crisis, these so-called civilized people will kill each other. (Clown)

Create a little commotion, disrupt the original order, and then everything becomes chaos, and I am the representative of chaos. Do you know the benefits of chaos? It brings fairness. (Joker)

You see, madness is like gravity, sometimes all it takes is a nudge. (Joker)

I believe that what doesn't kill you makes you weirder. (Joker)

As for Batman, Batman does not need to be portrayed. If the Joker is a madman who falls off a cliff and wants others to fall with him, then Batman falls off a cliff and desperately stops others. The person who fell, the Joker is a madman who collapsed and went crazy under the blow, and Batman transformed into a protector in the dark under the blow and despair. The Joker is madly jealous of Batman and wants Batman to collapse like him, but he doesn't. I hope Batman will never collapse, because the Joker, like everyone else, wants a protector. In fact, when he fell into the chemical pool, the Joker was eager for Batman to catch him