Songfacts®:

• Titled after her birthday, "929" is a candid stream-of-conscious reflection on Halsey's many life experiences. Over the course of just under three minutes, the singer details her struggles with self-esteem, anxiety, giving up smoking, and hair loss. Tumultuous past relationships and personal fan interactions also get examined.
  
  Halsey introduced the song at her album release party by confessing, "This is probably the most uncensored song I have ever written in my life, so I'm happy to play it for you guys tonight."
• In addition, Halsey touches on her relationship with her father.
  
  And I've stared at the sky in Milwaukee
  And hoped that my father would finally call me
  And it's just these things that I'm thinking for hours
  And I'm picking my hair out in clumps in the shower
  
  Halsey explained to Beats 1's Zane Lowe that she wrote the lyric about her Hopeless Fountain Kingdom Tour stop in Milwaukee in June 2018 that she remembered "vividly." The New Jersey pop star added that she and her father maintain a good relationship now, but at the time she "wasn't being receptive to any male energy" in her life.
• The track came together as a near-freestyle in the studio booth. "I barely wrote anything down," she wrote in her Spotify Storyline about the song. "I just started spilling all of my thoughts about myself and my fans and my family, and I admit so many faults and flaws all in one go. It's forgiving, however, it ends with the acknowledgment that I am learning and growing, minute by minute."
• Halsey first teased the song on August 12, 2019, after she'd got the numbers "929" tattooed onto her right hand.
• Halsey starts off the song by revealing she was "born at 9:29 a.m. on 9/29."
  
  She unveiled the official video on September 29, 2020, her 26th birthday. Helmed by the singer's tour videographer Peter Donaghy, the nostalgic clip looks back on her life thus far, including home movie footage from her childhood.