Songfacts®:

• The lyrics appear to document Stefani's breakup with Gavin Rossdale:
  
  Never thought this would happen
  I've let it sink in
  You're gone
  
  Stefani filed her petition for divorce from Bush frontman Gavin Rossdale on August 3, 2015. The singer had been married to Rossdale for 13 years, tying the knot in 2002 after the pair met in 1995.
• During an appearance on US breakfast show Today on October 27, 2015, Stefani was asked by host Matt Lauer if the breakdown of marriage with Gavin Rossdale had inspired the song. Caught off-guard by the question, the singer replied: "Oh my God, put me on the spot! What I'll say about that is that I've never put a record out where I'm actually going through things in real time."
  
  She added, "I wrote that song a couple weeks ago, and then I sat in front of a camera in a dressing room, randomly not making a video, just to do some video for the screens behind me (onstage), and then it went out and it was the (official) video. It's all very real."
• The songwriting duo of Justin Tranter and Julia Michaels worked with Stefani on this track. Tranter and Michaels were the go-to moving-on-from-a-breakup song team in 2015: they also co-wrote "Sorry" for Justin Bieber and "Good For You" for his ex, Selena Gomez.
• Speaking to KIIS-FM's JoJo Wright, in November 2015, Stefani revealed the story of the song. "The song was not written that long ago. Like, I want to say maybe a month and half ago, which is crazy," she said.
  
  "I had been writing, writing because my life blew up," Stefani added referring to her breakup with Gavin Rosedale. "Everybody knows that my life blew up last February. I'd just been dealing with that. Unexpected. I was going along thinking that was going to be the rest of my life and it's not. I don't know what happened. I've always wanted to write music so desperately because doing it is one thing that really validates me for myself.
  
  There was one night, the epicenter of the whole thing - that's the most I can say about that - and the next day I wrote the chorus to 'Used to Love You,' but I didn't know it was 'Used to Love You.' I just had written all this stuff and it had happened to be in there buried in a bunch of lyrics that I had written," Stefani continued. "I went to the studio and I had written all these songs that I feel like the record company was like, 'We think it's really great and very artistic. Maybe you should just put it out as an artistic body of work.' It kind of felt like a punch in the stomach, like all the wind got knocked out of me. They basically said they didn't think anyone would relate to it and it was too personal. I was like, 'Oh! Ouch!' But I don't know if they were trying to, like, I don't know."
  
  "The next day I wrote 'Used to Love You,'" she concluded. "Sometimes you need someone to just pinch you or slap you in the face or punch you in the stomach, which is what they did."
• Gwen Stefani debuted this song during her MasterCard Priceless Surprises concert in New York City on October 17, 2015. "I just want to share a song that I wrote recently," she told fans. "This song is really special." As she performed the tune, a video (directed by Sophie Muller) featuring the No Doubt singer's own emotive facial expressions played on a large screen behind her.
• Speaking to Vanity Fair, Stefani said the song is more about forgiveness than it is revenge: "It's admitting, I used to love you and now I don't," she said. "I opened this channel to writing again - it was me being honest, being real."