The Entire Movie While Joker's ending can certainly be interpreted in a variety of ways, many are suggesting that the vast majority of the movie takes place within Arthur's mind.
There is reason to believe that all of the action of Joker takes place within the confines of Arthur Fleck's head. The Joker movie makes it clear that not all of the events we see are real and that much of the action is imagined or hallucinated.
Before the credits roll on Joker, audiences are asked to suspend all belief that what they've been watching is actually true. As the movie heads into its final chapter, it becomes increasingly clear that the Harlequin of Hate has been telling a few porky pies.
Later, Arthur goes to Arkham State Hospital and steals his mother's records, and finds out that he was in fact adopted, and that Thomas Wayne is not his father and that Penny is not his true mother.
In Joker's case, pseudobulbar affect probably occurred secondary to severe traumatic brain injury (TBI). A number of studies have established that TBI increases the risk of mood disorders, personality changes and substance use disorders.
Joker Director Finally Explains That Last Crucial Scene
What mental illness Joker has?
The psychopathology Arthur exhibits is unclear, preventing diagnosis of psychotic disorder or schizophrenia; the unusual combination of symptoms suggests a complex mix of features of certain personality traits, namely psychopathy and narcissism (he meets DSM-5 criteria for narcissistic personality disorder).
Penny is not mentally well, as she possibly has schizophrenic and narcissistic tendencies hinted in the film. She is shown to be neglectful as she didn't save Arthur as a child from his abuse.
I asked Todd how Thomas Wayne would've know Arthur's mother. The backstory was that Arthur's mother had worked for Thomas in his home, and she was a beautiful woman who Thomas was attracted to and it led to a physical relationship. Later in life, she's in and out of mental institutions.
Arthur has a neurological condition that causes him to laugh involuntarily, which the film suggests may stem from a traumatic brain injury caused by childhood parental abuse. Throughout the film he experiences undefined psychiatric symptoms that include paranoia, visual hallucinations and delusions of grandeur.
Jared Leto portrayed supervillain Joker in the comic book-based movie and his version of the character had the word “damaged” tattooed across his forehead, an idea that Ayer proposed.
The Joker commits a crime and, cornered by the Batman at the Monarch Playing Card Company, throws himself into a vat of chemical waste. He survives, but becomes horribly disfigured in the process. This is the first and earliest attempt at providing a background for the Joker, written in 1951.
The comics series The Joker: The Man Who Stopped Laughing features Batman's nemesis get pregnant after a curse is placed on him, Daily Mail reported. Eventually, the Joker "vomits a sort of brown goo" that transforms first into a baby boy and then into a mini version of himself.
When Jerome seemingly died, his corpse went through a procedure which attempted to revive him. When the procedure seemed to fail, a cult decided to instead remove Jerome's face due to his criminal reputation.
Arthur Fleck, later known as the Joker, is a failed comedian who, following his great lack of success and respect, loses his mental stability until he becomes a nihilistic, sociopathic killer calling himself Joker, aiming himself to make Gotham smile in his way.
Director Todd Phillips considered the character's body size as one way to represent his vulnerability. It is important to emphasize that unlike most people who diet to lose weight or who develop an eating disorder, Phoenix's weight loss was intended for the short amount of time it took to shoot the movie.
The Joker (or Arthur) appears to have a complex mix of diagnoses, including pseudobulbar affect – a rare condition consisting of uncontrollable laugher or crying, and possibly a psychotic illness, evidenced by his apparent hallucinations about the subject of his affections (played by Zazie Beetz).
Everything seems to be going swimmingly until Arthur lets himself into Sophie's apartment after his mother's death, and she barely recognizes him. Viewers then see alternate versions of Sophie's scenes where Arthur is interacting with thin air, clearly indicating that the entire relationship was a fabrication.
There's no story where the Joker and Batman are brothers. The only supposed brother batman may have is Lincoln March, who claims Martha Wayne gave him to an orphanage before she had Bruce and claimed his official name is Thomas Wayne Jr but that's never been proven and it's kinda forgotten.
It is then revealed that the Joker's real name is "Jack Oswald White." Martha then shares that she visited the Flashpoint universe's version of Jack Oswald White, discovering him to be a struggling family man supporting his wife and a child as a janitor at Wayne Casino.
In the documentary I Am Heath Ledger (via Digital Spy) it's revealed that, in order to keep the prosthetics in their place as they got loose when he spoke, Ledger had to lick his makeup to keep it in place, and it ended up becoming part of the Joker's manic personality, as well as his most memorable mannerism.
Joker suffers from a rare disorder, Vrolic Syndrome, which gives him incredibly brittle bones. He was born with severe fractures in his legs, which is seen by his use of crutches and leg braces.
Mid-stab, Batman instinctively breaks the Joker's neck just enough to paralyze him. Joker laughing his last laugh while he snaps his own neck. As a group of innocents, who believe that Batman murdered the Joker, scream and flee, Batman confronts his opponent.
