Stills wrote the song after being inspired by the tag line -- "If you can't be with the one you love, love the one you're with" which was a frequent remark by musician Billy Preston. Stills asked him for permission to use the line in a song and Preston agreed immediately.
Several acts have since covered the song. The most notable cover came in 1971 from The Isley Brothers, whose unique gospel-driven cover of the song sent it to the charts again reaching number three R&B and number eighteen pop, giving the group their fifth US top 40 pop single.
A version was released by early 1980s UK pop trio Tight Fit in 1983, but failed to chart. Bucks Fizz covered the song as their eighteenth single in 1986 reaching UK #47.Will Young also recorded a version for his second album, Friday's Child. In 2006, Dennis Rollins produced a further cover on the album Big Night Out!. The Chantoozies produced another cover, releasing it as a single from their second album Gild the Lily, becoming their biggest selling single.
Another notable cover of this tune is from the Danish act Ray Dee Ohh's second album from 1990 Too. This was a solid up-tempo, classic pop/rock version.
In 2012, the song was featured in Ridley Scott's sci-fi movie Prometheus. Idris Elba sings a short phrase from the song after describing a possibly fictional account of how his squeezebox used to belong to Stills.
In the 2003 The Simpsons episode Treehouse of Horror XIII segment Send in the Clones, Marge is worried that the real Homer was the first over the cliff chasing donuts and the one still with her is a clone, until the clone Homer gives her a backrub and this song starts playing.