I know. But Batman doesn't understand Joker. He never has. Not in the comics, not in television and not in TDK.
What makes
you different?
Bruce didn't understand him at the beginning, but he seemed to get into his psyche more to the end. Not open to interpretation? Maybe.
He is alone. He's the only one who sees the world for what it is. This is both a badge of pride for him and depressing. Like being king of the world...there's nobody else you can relate to. This is also why he made Harvey into Two-Face. He wanted a kindred spirit.
Then Batman DO understands him. I patiently wait until you make up your mind.
Obviously there's frustration in the character, but I thought the interpretation was completely different in TDK than it was in TKJ.
Based on what? I just wanna know, because you seem to be contradicting a popular and common opinion.
For the world to exist the way it does, society is necessary. Yes. But the way it exists is not ideal. Joker sees the whole thing as a misconstruction. Society was built wrong. Look at the fundamentals and you'll see they're unfair.
I see them. I still don't see how they're unfair. What kind of society do you mean? Let's stick to the current ones... Authoritarian dictatorship, socialdemocratic government, representative democracy, socialism with open market, monarchy with legislative and executive power, symbolic monarchy...
.... you name it. We'll see how is it that they're unfair and what may be the cause of it. And I guarantee you, you won't get an easy answer in no way.
Because you'll have to ask yourself in which ways are they unfair, and in most cases the answer will have a direct parallel in Life. Life is mostly unfair for many people. There are contradiction intentions, apathy, lacks of natural resources, failed economic and social ideologies, unfulfilled expectations, good and bad intentions...... zillions of reasons in which life is unfair. Hell, just the act of courtship in the first world is unfair to many men who don't know how to attract the women he wants, and women surely don't make it easy... they have their reason for it.
Should men fight for a new social order in which women are their sex slaves?

You may answer 'yes', but the answer is no. You struggle against obstacles in the best possible way without harming others. And that's what the Joker couldn't afford to do, because he was mentally scarred. Batman is scarred too, but not enough to desire the destruction of society to feel better about himself.
Do I like society? Yes and no. there's a very large part of me that hates it and agrees with the Joker that it should be displayed for the farce that it is. Our music does that in a less destructive way than blowing up judges and burning DA's faces off. Partially because we're not brave enough to do that, partially because we know that if we do we'll be destroyed and no longer allowed the freedom that we do have. And partially because we're to empathetic to bring that kind of misery. But on the other hand, society offers comforts that anarchy does not. Joker doesn't need these comforts, therefore he can go all the way.
Comfort? Do you think it only gives you comfort? Come on. For starters, social systems gave you the TOOLS to overthrow them. They gave you music, they gave you music history and precendts to get inspired from, they gave you social awareness, they gave you language, they gave you film, they gave you comics, they gave you Batman, and they gave you Christopher Nolan.
And it even gave you the frame of opportunity to seize those things.
To turn against that is the real hypocrisy. You can struggle to perfect social norms, but you don't turn against the whole system. And not because you're not brave and cold enough... it's because there are lots of good things that you don't notice so much.
'People remember more the times they cry than the times they laugh'... there you go, make a tatoo with that phrase and keep up with your music.
The message is basically this: Nobody knows what life is all about, so stop acting like what you do is "the right thing." My brother and I say this with art, Joker does it with homicide.
That's why the Joker (and Ra's al Ghul, don't forget him) is being more ignorant than Batman. He is ignoring a simple, undeniable truth... there are still lots of good people in Gotham. There are still good norms in society.
And that's what makes Batman wiser than them. He is more balanced, they're more radical... and obtuse, and one-sided.
Joker doesn't control himself. He acts on impulse.
.... Hey, you're being delusional! And you can't prove that point
That's what I find so beautiful about him. Somebody like me is constantly having to repress half of the things I feel because they'll get me arrested or shunned by society.
.... And now you're explaining why you're connecting with the guy in a subjective and poorly thought way! Now it's so easy for me to win this argument...
When we meet him, Joker was already shunned by society, so he doesn't get any of society's comforts. Therefore he doesn't need the security blanket society offers, since to him it does nothing. He's free to do what he wants and what he wants it to show everyone what is wrong with society.
Wrong, society has millions of opportunities for people with permanent scars and traumatic past experiences. He could have a very good life if he wanted. He far from shunned by society. He doesn't have to fall in line either... if he wants to get away from society, he can become a hermit. But no, he choses to kill and maim to feel better about himself... he's probably more bound to society than Ra's al Ghul. You should admire Ra's instead.
homicide is pretty natural to man as well.
No, homicide is natural to animals. Yes, we're animals, don't get darwinist with me, but we're still quite apart from the rest of the species... you wanna know why?
Control of impulses.
If I hate my mother-in-law, I don't kill her. You know why? Because that would set me apart from society, and I would stop enjoying many of the privileges achieved by combined effort in community. Killing her is not the intelligent thing to do...
... and we are INTELLIGENT.
That's what sets us apart from animals. We repress our instincts to (hopefully) do the most intelligent thing to do.
That's what makes us HUMANS.
That's what's essential to us.
The Joker killed all of his partners in the bank heist... ONLY after they completed the job. He waited until he received the result of their combined effort... he repressed his homicide instinct..... he HAD A PLAN.
Which makes you doubly wrong about him.
That fixation on "doing" that society has created is what the Joker wants to denounce. What is so great about society? Where has it gotten us? This? The Joker looks around at the world man has built and is unimpressed.
And could he be impressed? He was hurt, it's personal to him, he sees the world in a subjective and mildly irrational way, he's not objective at all... he's resentful.
Society has still lots of good things that aren't worth sacrifying. When you lay your desire to debate aside, you'll understand it. Be objective. It's a good thing.