Brain: These are bad for me.

Nicotine: Shut up.

Brain: They're polluting my body.

Nicotine: Shut up.

Brain: The simple fact is that I can live without them.

Nicotine: Shut up.

Brain: I don't need…

Nicotine: Shut up.

Brain: Yeah, but…

Nicotine: Shut up.

Brain: I…

Nicotine: Shut up.

Brain: Fine!

smokes cigarette

Brain: There.  Now I'll just stop and…

Nicotine: Shut up.