The lyric 'We made a start, be it a false one I know' may be relevant to Harry and Louis moving in together in September 2011. Similar to ' Strong', ' Happily', ' Something Great', ' If I Could Fly' and ' Home', fans speculate the song to possibly be about Louis Tomlinson and Harry Styles's closeted relationship. 'Literally a week Ed comes round to my house with his manager one night, turned up around 11 o’clock and said ‘Do you like this song?’ and he played me ‘18’ and it took me about a millionth of a second to say yes,” Simon Cowell is a fan of the song and talked about how he arranged for Ed Sheeran to write it. On November 17, 2014, the band announced 18. On September 8, 2014, the band announced the release of their fourth album, Four, on the Today Show. Lyrically, 18 describes a past relationship the narrator has not moved on from, and would like to start over again, with a more mature perspective. 18 is the fourth track from One Direction's fourth studio album, Four.