Eternal Sunshine Of The Spotless Mind

Charlie Kaufman (Interview from Published Screenplay) claims that this movie idea was being developed before the release of the movie Memento.

Charlie and Michel (Full length commentary on original region one DVD) explain that the Elephant Parade was added during filming.

There is one memory that Joel specifically asks to keep. It is the scene in which Clemetine describes how she felt ugly as a child, and had an "ugly girl doll," named Clementine. In the screenplay this scene is written to include a passage/story from the Velvetine Rabbit. The shooting script contains the version of the scene that we see in the film. (Interview from Published Screenplay)

Eloisa to Abelard is written by Alexander Pope (1688-1744). Mary Svevo attempts to remember the name, but reverses the first and last name, calling the poet, "Pope Alexander." Mary quotes the following lines of the poem and deems them "fitting" given the memory erasing procedure already well-underway.