Regarding Margie/References

Trivia

 * It is revealed Milhouse is (or was) lactose intolerant. This has also been mentioned in the flashback episode 'Lisa's Sax" wherein Milhouse says that the normal kind of milk could kill him.
 * Homer shows Marge a picture of him punching former president George Bush, a reference to the seventh season episode "Two Bad Neighbors", and then shows a picture of him punching current president, George W. Bush. This is the first appearance of George W. Bush and now every living president has made an appearance on the show. The most recent President who has not been shown in animated form is Herbert Hoover.
 * During the credits, Homer claims that Danny Elfman is only there because he's friends with Richard Sakai.
 * The opening gag 'I will not leak the plot of the movie' is a reference to the upcoming Simpsons movie.
 * Bart's scheme of painting house numbers on curbs to make money is possibly based on the real childhood of longtime Simpsons writer George Meyer.

Cultural References

 * The title is reference to the movie Regarding Henry, in which Harrison Ford plays a man with amnesia.
 * The scene where Marge and Homer go to a wedding uninvited is similar to various scenes from Wedding Crashers.
 * Homer writes on the sidewalk that the '74 Oakland A's are the best team ever. Soon after, several members of the team drive by and thank Homer for remembering them. Sal Bando and Gene Tenace, two members of the actual team, make cameo appearances.
 * Marge's amnesia is caused when she passes out and hits her head on a stool, a reference to the film Million Dollar Baby.
 * Marge's quote, "Et tu Zud?" is reference to 'Et tu Brute,' from Julius Caesar by Shakespeare.
 * When Ned holds the comics for Bart and the others, the one on top is called Little Jesus, a parody of the Little Lulu comics.
 * One of the cleaning products Marge used was Mop 'n' Brag, a spoof of the product Mop 'n' Shine.