The song was inspired by the birth of the band's lead singer Matiu Walters' daughter.

Her birth made Walters reframe his life, and the reasons why he creates music, and wanted to create a song that could impart "inspirational wisdom" to his daughter, even though she was too young to speak.

[1][2] The single was written and recorded in the band's studio in Dunedin as a live studio session, in a similar way to how the band recorded their first songs together.

[3] "Before You Leave" was released as the lead single from Castle St on 19 August, a month and a half before the album.

[5] In November during their visit to Auckland, Canadian pop duo Neon Dreams performed a cover of the song.