Transcript:
Goat: Have you ever had surgery, Rat?
Rat: Just once. I had a filterectomy.
Goat: What's that?
Rat: It's where they remove the filter between your brain and your mouth.
Goat: And now I understand everything.
Rat: If it pops in here, it pops out of here.
Not exactly an original concept; Sophia’s filter was burned out by a stroke on Golden Girls, and Dan Fielding claimed to have been born without one on Night Court.