There will be some spoilers.
Put on a happy face
Joker was a film that itself was an agent of chaos. The film and the character in the film were symbiotic, where one couldn't exist without the other. They needed each other in the most beautiful poetic way, much in the same way as Travis Bickle and Martin Scorsese needed each other. Joker was a weird film where the film was all about him and simultaneously wasn't about him at all. The film was micro-sphere driven but had macro-sphere implications. 
A Brief History: Homo sapiens, us, have been around for about 200 thousand years, evolving for millions of years prior to that, give or take. The agricultural revolution kicks in and us, hunters and gathers have finally found some level of stability. Civilizations form, we agree to give up our freedom for security but at a cost. The illusion of freedom isn't free, you have to pay to feel you are free even when you are not. This becomes the foundation to our society, through wars and the fall of other civilizations, ours is the latest version of human beings that can and cannot get along when money is involved.
Plan and simple, Joker is about a failed system of who has and who is never allowed to have. It's also about how we can't truly relate to other people. We all want to believe we can, we call that being positive or optimistic, but in actuality we are in our own heads, viewing the world through our perspective and only imagining what another's life must be like. In the end we don't know, we are not starving in Africa or a Syrian refugee. Arthur Fleck is a product of this failed society and that's what's pissing people off the most, because by accepting that prognosis is accepting that we live in a failed project. All the decisions we make in our day to day lives whether sit in on corporate merger meetings or defending criminals in court or paying for our groceries at the supermarket or cold calling people trying to convince them into buying a lifelong subscription to some bible club, this structure is all we know, we are bound to it. Joker holds a mirror up and we don't like what we see because when he is looking in a mirror we don't see him, we see ourselves.
I thought about going into the girlfriend neighbor is real or isn't or is any of this real by the end and then in my end, from what I take from the film, is it real or isn't, is missing the point. The film is a mirror.This film is Nietzsche's undoing everything you've been taught, it's Rimbaud's derangement of the senses, it's confronting Jung's shadow, it's Macbeth's rise to power. Joker is the fallout of The Notes from Underground and Maldoror as well as Charles Baudelaire's Intimate Journals. Joker is what Kierkegaard warned us about, the fear we have about our own freedom.
Arthur lost all his support systems and fell into chaos, this isn't about condoning what Arthur/Joker became but it is a lesson to us all to touch the people in our lives. It's about realizing when Plato said to 'be kind because everyone is fighting a battle', that he meant it. It's not a cute saying but during his time it was meant to be understood. That's where empathy comes in and where the system fails.
The fact is our world has owners. We never want to be thought of as something that is owned but we are, and are we able to get over how fucked up of a concept that even feels like, then we are able to start to peel back the layers of the onion. Classism was a major focus in the film, are we equal, who gets to die on the Titanic and who gets away? In the film there were all these little Joker-bots that claimed to have a cause and they were all full of shit. Their recourse was destruction without any level of understanding of what they where even doing.
What is the point........
The Joker isn't the 'agent of chaos' he's the product of it. Sadly he's in us all and that's why we hate him, but more importantly why we love him simultaneously is because he is us. Our ying and yang battle is on going and within us all, so the film isn't an examination of this tortured man that evolves into this crazed joker killer. The film is about our own fantasy. Arthur Fleck was never the villain. We are.
What is the point.....
The point of the film isn't to understand it.
#joker
#batman