* AgeLift: Everyone is supposed to look like they're forever 25 - and only Creator/AmandaSeyfried was that age during filming.
* DawsonCasting: An odd example since most important characters even though they ''look'' young are often quite old. Cillian Murphy in particular is in his mid 30's playing a character a decade younger (biologically speaking). And Music/JustinTimberlake is in his 30s. Of the entire main cast, only Creator/AmandaSeyfried was really 25.
* PlayingGertrude: An extreme example as Justin Timberlake is actually two years older than Olivia Wilde, who plays his mother. Justified as the film is set in a world where no one ages anymore.
* WorkingTitle: It originally was going to be titled "i'm.Mortal."
** Was also listed as "Now" on IMDB for a while.