Songfacts®:

• "If I Can't Have You" is a song about a girl that Shawn Mendes is obsessed with:
  
  I can't write one song that's not about you
  Can't drink without thinking about you
  
  Unfortunately the girl doesn't seem to feel the same way.
  
  I'm trying to move on, forget you, but I hold on
  Everything means nothing, everything means nothing, babe
  
  The infatuated singer just can't get her out of his mind.
• Shawn Mendes penned the song with his regular writing partners Scott Harris and Teddy Geiger. Their previous collaborations include his hit singles "There's Nothing Holdin' Me Back," "Treat You Better" and "In My Blood."
  
  The fourth credited songwriter is soul and R&B singer Nathaniel Mercereau, who has worked a lot with Leon Bridges. He previously contributed to the writing of Mendes' "Lost In Japan."
• Mendes and company originally wrote the song for Dua Lipa. But as he played it in the studio, he realized it tied in with the mood he wanted for his new music, so the Canadian decided to keep it for himself.
• Speaking during a YouTube live chat, Mendes said he had the song's melody stuck in his head for two months before he was able to complete the track. However, once he got into the studio with the other songwriters, they quickly completed it. Shawn said, "It seems to be a pattern with my favorite songs. When it feels right it comes quick."
• Mendes said his biggest inspiration for the song musically was the British group The 1975. He was obsessed with their A Brief Inquiry into Online Relationships album while making this track.