Joker is a beautiful movie that shows the progressive derangement of Arthur Fleck, who turns into one of DC's favorite villains: the Joker. Joker is about how a regular guy, Fleck, transitions into this maniacal villain. We know that the Joker thinks that he's a comedian (while still being self aware) and everything he does is sort of an act -- but attached to some good in his view -- and in Joker, we finally see how he gets to that point psychologically. I'm thinking about the scene in the hospital
(when he kills his mother)
when he says, "I used to think my life was a tragedy, but now I realize that it's a comedy". What specifically triggers that change in his attitude towards his life? On first glance, it might seem like the answer to that question is obvious, but there's so much going on in the movie at the same time that I'm confused about what specifically causes this change.