"Superheroes don't smoke."

From the 2007 documentary about costumed panhandlers outside Grauman's Chinese Theatre, Confessions of a Superhero:

"Superman" and "Ghost Rider" are walking down the Walk of Fame.

Superman: Ya gotta remember there's a lotta dos and don'ts, ah, as a superhero... but if you abide by 'em, you do okay.

[silence]

Superman: Well, just remember, superheroes don't smoke. [pause] It's an image.

Ghost Rider: Except Ghost Rider.

Superman: No. Ghost Rider doesn't smoke.

Ghost Rider: He's made of fire.

Superman: But, still, he doesn't smoke cigarettes. [pause] You can't make exceptions for something that doesn't exist. You'll never see Ghost Rider smokin' a cigarette walkin' down the street. It's just not proper.