Songfacts®:

• Here, Olivia Rodrigo sings of navigating a back-and-forth relationship with a moody boyfriend. The dude is totally inconsistent – some days he's happy and she's the love of his life, then something petty will make him go mad. She feels their romance isn't progressing; whenever she feels it's taking a step forward, a sudden and illogical outburst of anger sends it three steps back.
• The guy's inconsistent behavior is making Rodrigo wonder if there's something wrong with her.
  
  Never doubted myself so much
  Like, am I pretty? Am I fun, boy?
  I hate that I give you power over that kinda stuff
  
  The singer sang of similar feelings of inadequacy on "Drivers License," where she compares herself to her ex's new girlfriend.
  
  And you're probably with that blonde girl
  Who always made me doubt
  She's so much older than me
  She's everything I'm insecure about
• So why does Olivia stay with the moody dude? She sings in the second verse of how the emotional roller coaster ride he is giving her is a turn on.
  
  And maybe in some masochistic way
  I kind of find it all exciting
  Like which lover will I get today?
  Will you walk me to the door or send me home cryin'?
• Rodrigo wrote the song with her regular producer, Dan Nigro. Taylor Swift and her writing partner Jack Antonoff also get credited because the song borrows melodic elements from the pop princess' 2017 Reputation track "New Year's Day."
• Rodrigo is a self-confessed Swiftie, and the song title is a nod to her hero. 1 + 3 = 13, which is Swift's lucky number. She frequently sneaks in references to 13 in her music.
• Olivia Rodrigo plays the piano on this song. It is the only Sour track where she plays an instrument and also sings.
• When Olivia Rodrigo appeared on The Zach Sang Show she said the song originated when someone sent her a text message, which included the titular phrase. "I've never heard somebody say something like that, so I thought it would be a cool way to describe this toxic, sort of manipulative relationship."
  
  After coming up with the "one step forward" concept, Rodrigo wrote a verse and a chorus. Later, after returning home from a road trip, she had the idea to sing it over the chords of "New Year's Day."
• Dan Nigro came up with the idea of incorporating the birdsong at the beginning of "1 Step Forward." One morning he stuck a microphone out of his house window and recorded the birds chirping. Rodrigo said it adds "a cool ambiance."