The beginning of the episode shows Maggie's scene from the Simpsons short "Good Night". Then, in a parody of The Big Bang Theory opening sequence, a song plays to the tune of said show's theme song as the camera zooms through the universe. We get close to the planet Earth and learn a brief history of The Simpsons from the beginning to present day, while brief second screenshots of older Simpsons moments are shown. We then see the Simpsons run to the couch and sit on it, which then disappears out from under them.

The Simpsons (Channel 4)