Catherine Zeta-Jones' style of acting in this movie was modeled upon Katharine Hepburn's romantic roles.
Billy Bob Thornton speaks very fast in this movie because his character in The barber: l'homme qui n'était pas là (2001) speaks very slowly. They did the same thing with Steve Buscemi in The Big Lebowski (1998) and Fargo (1996).
Marylin's line, "Dismiss your vows, your feigned tears, your flattery / for where a heart is hard they make no battery" is from William Shakespeare's poem, Venus and Adonis.
Miles's line, "Whoever loved that loved not at first sight" is from Christopher Marlowe's poem "Hero and Leander".
Joel Coen: [Kubrick] The "beeping" sound effects of Herb's medical equipment are taken directly from Stanley Kubrick's 2001 : L'Odyssée de l'espace (1968), specifically the radar sound effects of the Jupiter pods.