[Spoilers for the Joker]

I saw the Joker today, and I have to say, it was not exceptionally violent, despite how the Joker killed 6 people, some of whom he shot while they were already dead. Much scarier than the violence in the film however, is the portrayal of uncertainty that can come with mental health.

The Joker, aka Arthur Fleck,  met a single mother, one of his neighbours, who he felt sympathized with him after she mimed shooting a gun to her own head. He stalked her for a day, and she said she had noticed, and seemed not to mind. He invited her to a comedy night, and after killing the three men on the subway, she opens her door for him and he kisses her without explanation. She reciprocates the kiss.

At the comedy club, Arthur seems uneasy, laughing anxiously and uncontrollably with stage fright - too scared to tell his own jokes, but appearing to the audience like he can't keep a straight face. The audio cuts to music, and the crowd loves him, he finds his voice, and the woman from before is in the adoring crowd.

When his mother has a stroke, she is at his side comforting him.

Around this point in the movie, Arthur realizes that his mom has been writing to Thomas Wayne (now a politician, no longer a physician), claiming that Arthur is Thomas's estranged son.

Despite the family resemblance, which is cinematographically emphasized when Arthur confronts Thomas, claiming to be his child, Thomas suggests that not only is Arthur not his bastard child, but that his mother had adopted him, then let her then boyfriend abuse him when he was very young, leaving him with brain damage. Arthur finds records that suggested this was true, and that his mother had been lying about her scandalous relationship with Thomas since he had been small, and that after allowing him to be abused, she had been admitted to Arkham.

Returning to his neighbour's apartment, now the real woman he had been fantasizing about in his delusions was in front of him, and alarmed that he has come into her home. He realizes all at once that she hadn't cheered on his crimes, nor invited him to stalk her, didn't see his standup show, didn't want to make out, and hadn't comforted him when his mother had a stroke.

This is further cemented when his personal favourite talkshow host plays a recording of his comedy performance on his program, only to highlight how terrible it was.

After learning his mother was diagnosed with psychotic delusions, as well as narcisistic personality disorder, and that the woman who had been his most consistent comfort had been a delusion of his own, some things start to unravel for him, and he realizes that just like he can't trust his delusional mother, he now cannot trust himself. He is aware that his memory is faulty, and how his reality differs from others', but is still unsure of what is actually real.

In his other, famous origin story, the Killing Joke, the Joker states, "if I'm going to have a past, I'd prefer it to be multiple choice!" and this movie takes that ethos to the extreme. The day of his birth as the Joker, after he is arrested after murdering his former idol on live television, clown gangs stage a massive riot, and Thomas and Martha Wayne are gunned down by this story's Joe Chill, their original killer, this time a clown wearing a mask, and proclaiming their death as an act of revenge, before ripping Martha Wayne's pearls off to add insult to injury.

For decades, Batman's origin story involved Joe trying to steal, and clutching Martha's pearls, and Thomas intervening, before Joe shoots them both. The original frames Batman's origin with his parents dying an unjust and heroic death, martyred by crime, but in the Joker's world, they die from a senseless act of violence, brought on to spite the Wayne's bourgeois lifestyle. The Joker sees their deaths as a joke, and this movie is his life from his own perspective.

The Joker, having previously believed Bruce to be his half brother, tries to make the serious child smile, even clutching his gums through a fence - of course in the Joker's own narrative, he gets to make his all too serious nemesis smile the first time they meet, a goal of the Joker's since the Killing Joke and beyond.

As the riots continue, after Martha and Thomas are shot dead, rioters free the Joker from the cop car that had taken him after his live TV stunt. However, not long after the Joker seems to recover, a final scene in an Arkham Asylum intake room, where the Joker undergoes questioning, calls into question whether or not he even had a whole social movement egging him on in the first place.

Psychotic delusions and narcisistic personality disorder. The same symptoms that his mother had. Although the abuse he suffered as a child is as good an explanation as any to explain his situation, the fact of the matter is that psychosis is heritable, so if he inheritted that from his mother, then was she telling the truth? The scary thing about the delusions that plague Arthur Fleck, is not that nothing he says is reliable because he is delusional, its that other people will treat him like he is crazy regardless of whether or not he is right.

Regardless of whether or not he had a mom who supported him, regardless of whether or not he made Bruce Wayne smile, regardless of whether Bruce's parents died as martyrs, regardless of whether or not he had a supportive love interest, and regardless of whether or not he had inadvertantly started a social movement; he knew he wouldn't be believed either way, and to him, that was the biggest joke of all.

And why should he care? Except that if he inherited his mother's symptoms, in all likelihood he wasn't adopted, and of all the delusions in the movie, a rich Thomas trying to cover up his affair with Arthur's mentally ill mother is the most believable. Being gaslit hurts most when you don't even know what to believe yourself anymore, and knowing that the Joker deals with that is scarrier than what he did to any of his victims.