It was written by Daniel, Finneas O'Connell, Caroline Pennell, Jay Stolar, Mick Coogan and Sean Myer, with production handled by O'Connell and Sean Myer.

An official remix with American singer Selena Gomez was released on June 26, 2020.

[1] Another remix adding American rapper Lil Mosey as a featured artist was released on July 31, 2020.

[2] The music video for "Past Life" was directed by Vania Heymann and Gal Muggia and was officially released on July 14, 2020.

On August 18, 2020, Daniel performed a solo version of the song in a medley with "Falling" on The Tonight Show with Jimmy Fallon.