"Memories" is a dance song characterized by "nostalgic" synthesizer,[7] an "anthemic" drum and bass influenced chorus,[6] with "powerful beats" and "fast-paced rhythms".

[8] The lyrics of the song have been described as "introspective" and "youthful",[10] with Gabe Finch writing for Illustrate Magazine that they "invite listeners to reflect on moments gone by and the emotions they evoke.

Writing for NME, Carmen Chin called the song's chorus a "masterpiece", noting that "the track comes alive when the band's layered, sprightly vocal harmonies come together.

[15] Directed by Jinooya Makes,[16] the music video for "Memories" was released simultaneously with the song on August 21, premiering on SM Entertainment's YouTube channel.

"Memories" was shot consecutively with "Siren" and "Get a Guitar" over a five day period in July 2023 at various locations in the Greater Los Angeles area, including Thousand Oaks and the Southern California Railway Museum in Perris.