The movie trivia in Homer's brain is true. Stanley Kubrick's first choice for The Shining (1980) was Robin Williams, Ronald Reagan was long-rumored to have been considered for Casablanca (1942), and John Travolta was not in Grease 2 (1982).
One of the dreams-within-dreams is a recreation of the animation style from the first season of the show. The voice actors performed the characters differently back then.
The character of Robin Williams is voiced by Dan Castellaneta. Castellaneta voiced the genie in the Aladdin TV series. Williams voiced the genie in the original movie.
When Homer and Bart are fishing, the pig waste silo from the Simpsons movie is visible in the background.
The title is a reference to "How I Met Your Mother".