My all time favorite.

Wizard: Look at it this way. A man takes a job, you know? And that job - I mean, like that - That becomes what he is. You know, like - You do a thing and that's what you are. Like I've been a cabbie for thirteen years. Ten years at night. I still don't own my own cab. You know why? Because I don't want to. That must be what I want. To be on the night shift drivin' somebody else's cab. You understand? I mean, you become - You get a job, you become the job. One guy lives in Brooklyn. One guy lives in Sutton Place. You got a lawyer. Another guy's a doctor. Another guy dies. Another guy gets well. People are born, y'know? I envy you, your youth. Go on, get laid, get drunk. Do anything. You got no choice, anyway. I mean, we're all fucked. More or less, ya know.

Travis Bickle: I don't know. That's about the dumbest thing I ever heard.

Wizard: It's not Bertrand Russell. But what do you want? I'm a cabbie. What do I know? I don't even know what the fuck you're talking about.

Travis Bickle: Maybe I don't know either.