That's a Simpson's reference, if you didn't get it. "Annoyed grunt" is how it shows up in the script, resulting in that unforgettable utterance from the brilliant Dan Castellanetta.
The reason? I totally missed National Punctuation Day! It was September 24. Check out this cool little site with ideas on how to celebrate the day, letters and photos from readers and, of course, products to buy. My favorite? A T-shirt that asks "Is there a hyphen in anal-retentive?" Which would go along really well with my "Good grammar costs nothing" T-shirt.
Mark your calendars for next year!
Via Language Log