Arthur Fleck: [written in notebook] The worst part of having a mental illness is people expect you to behave as if you don't.
Arthur Fleck: I used to think that my life was a tragedy, but now I realize, it's a comedy.
Arthur Fleck: For my whole life, I didn't know if I even really existed. But I do, and people are starting to notice.
Arthur Fleck: You don't listen, do you? You just ask the same questions every week. "How's you job?" "Are you having any negative thoughts?" All I have are negative thoughts.
Arthur Fleck: How 'bout another joke, Murray?
Murray Franklin: No, I think we've had enough of your jokes.
Arthur Fleck: What do you get...
Murray Franklin: I don't think so.
Arthur Fleck: ...when you cross...
Murray Franklin: I think we're done here now, thank you.
Arthur Fleck: ...a mentally ill loner with a society that abandons him and treats him like trash?
Murray Franklin: Call the police, Gene, call the police.
Arthur Fleck: I'll tell you what you get! You get what you fuckin' deserve!
[Joker shoots Murray in the head, killing him instantly]
Arthur Fleck: Is it just me, or is it getting crazier out there?
Arthur Fleck: I killed those guys because they were awful. Everybody is awful these days. It's enough to make anyone crazy.
Arthur Fleck: My mother always tells me to smile and put on a happy face. She told me I had a purpose: to bring laughter and joy to the world.
Arthur Fleck: [In Arthur's notebook] I hope my death makes more cents than my life.
Cop: The whole city's on fire 'cause of you.
Arthur Fleck: I know. Isn't it beautiful?
Arthur Fleck: Have you seen what it's like out there, Murray? Do you ever actually leave the studio? Everybody just yells and screams at each other. Nobody's civil anymore. Nobody thinks what it's like to be the other guy. You think men like Thomas Wayne ever think what it's like to be someone like me? To be somebody but themselves? They don't. They think that we'll just sit there and take it, like good little boys! That we won't werewolf and go wild!
Arthur Fleck: I know it seems strange, I don't mean to make you uncomfortable, I don't know why everyone is so rude, I don't know why you are; I don't want anything from you. Maybe a little warmth, maybe a hug dad, maybe a bit of common decency!
Social Worker: They don't give a shit about people like you, Arthur. And they don't give a shit about people like me either.
Arthur Fleck: Comedy is subjective Murray, isn't that what they say? All of you, the system that knows so much: you decide what's right or wrong the same way you decide what's funny or not.
Arthur Fleck: I had a bad day.
Arthur Fleck: I haven't been happy one minute of my entire fucking life.
Arthur Fleck: Everybody's telling me my stand-ups, are ready for the big clubs.
Arthur Fleck: [from trailer] She always tells me to smile, and put on a happy face.
Arthur Fleck: Do I look like the kind of clown that can start a movement?
Thomas Wayne: Gotham's lost its way. What kind of coward would do something that cold blooded? Someone who hides behind a mask.
Arthur Fleck: [from trailer] I don't want you worrying about money mom, or me.
Arthur Fleck: [In Arthur's Jokebook] I just hope my death make more cents than my life.
Murray Franklin: [from trailer] All that sacrifice, she must love you very much.
Arthur Fleck: [after killing Murray] Good night. And always remember... That's life!"
[lets out an Evil Laugh before a guard pounces on him]
Thomas Wayne: [after punching Arthur] Touch my son again and I'll fucking kill you!
Arthur Fleck: I just don't want to feel so bad anymore.
Arthur Fleck: I've got nothing left to lose. Nothing can hurt me anymore.
Penny Fleck: I mean, dont you have to be funny to be a comedian?
Thomas Wayne: [as Arthur is laughing at him] Is this a joke to you?
[punches Arthur in the face]
Murray Franklin: And finally, in a world where everyone thinks they could do my job, here's a guy who thinks if you just keep laughing, it'll somehow make you funny. Check out this joker."
[commenting on Arthur's failed stand-up set]
Murray Franklin: Do I understand that you did this to start a movement? To become a symbol?
Arthur Fleck: Oh come on, Murray. Do I look like the kind of clown that could start a movement? I killed those guys because they were awful. Everybody is awful these days. It's enough to make everyone crazy.
Murray Franklin: So that's it? You're crazy, that's your defence for killing three young men?
Arthur Fleck: No. They couldn't carry tune to save their life.
Penny Fleck: I never heard him crying, he's always been such a happy little boy.
Murray Franklin: Look what happened because of what you did, what it led to! There are riots out there! Two policemen are in critical condition...
[Joker starts to chuckle]
Murray Franklin: ...You're laughing. You're laughing. Someone was killed today because of what you did.
Arthur Fleck: [guffaws] I know.
[Arthur is making a little kid laugh on the bus]
Boy's Mother: Would you please stop bothering my kid?
Social Worker: Arthur... does it help to have someone to talk to?"
Thomas Wayne: Gotham's lost its way.
Arthur Fleck: You're just like the rest of 'em!
Murray Franklin: You don't know the first thing about me, pal. look at what happened because of you did. what it led to. there are riots out there, two police men are in critical condition- you're laughing, you're laughing. someone was killed today because of what you did.
Arthur Fleck: I Know!
Arthur Fleck: ...I had a bad day.
Sophie Dumond: This building... it's awful, isn't it?
Thomas Wayne: What kind of coward would do something that cold-blooded? Someone who hides behind a mask?
Detective Garrity: Mr. Fleck? Sorry to bother you. I'm Detective Garrity. This is my partner, Detective Burke. We have a few questions for you, but you weren't home. So, we spoke with your mother.