Warfield told the story of the song in an interview with AntiMusic
, where he explained that he and Adam usually start with a beat, but for this song, it was some lyric and chord ideas in his head that started the process. Said Warfield: "It was just a matter of getting it down and making sense of it. For this album a lot of the lyrics were sung in the car while driving around Los Angeles with the instrumentals playing, and when inspiration would strike I'd record the melodies into my iPhone. I first came up with the beginning of the verse and knew what the first few lines of the song would be, next I found myself singing, 'must be the sun' over and over, and while I knew the words were stupid and just a sketch of the rhythm and melody, it was still stuck in my head for days. At some point I went in the studio to try and put something down, and that's when I replaced Sun with One and the story took shape and tied into the beginning I'd been toying with."
The duo then added the "She says I don't need anyone..." part, and Adam added the chord change. Last came the bridge bassline, which Adam re-recorded after the first attempt right before he mastered the song.