Songfacts®:

• "That's Hilarious" is about the worst breakup Charlie Puth has been through. They dated for a year, and when she dumped him in 2019, the singer felt he'd wasted a year of his life. Now the tables have turned and she wants him back again, so Puth mocks her.
  
  You didn't love when you had me
  But now you need me so badly
  You can't be serious, ha-ha-ha
  That's hilarious, ha-ha-ha-ha-ha
• When Puth listens to the track, it brings memories of the hardest time in his life when he couldn't let somebody go. Though the experience with his toxic lover was a challenging one, he learned one important lesson: "Don't give your heart to someone who's still got a broken one."
• Charlie Puth produced "That's Hilarious" himself and co-wrote the track with his regular writing partner Jacob Kasher. Their other collaborations include the VoiceNotes hit songs "Attention" and "How Long," plus his previous single, "Light Switch."
• The musicians are:
  
  Guitar: Jan Ozveren
  String Arranger: Mattias Bylund
  String Synthesizer: Mattias Bylund
  Cello: David Bukovinszky
  Violin: Mattias Johansson and Conny Lindgren
• Close to the minute mark, there's a very low sine-wave bass that Puth ran through a Mike Dean plug-in that made it sound really distorted. "That is representative of what was the most turbulent time in my life, where I was most uncomfortable," he told Apple Music.