Lambert wrote this song by herself the day after she met her partner. She explained to American Songwriter magazine: "It's about that moment when you've found your person, that person that makes you feel like you've been holding your breath your whole life, and you've finally had your first real deep breath. And you sort of fabricated this feeling in your head over and over with all these relationships, so do you trust yourself that this is really the real thing? Could it possibly be that person? And it totally is. It could still go either way, and you hope they feel the same way."
Lambert explained the lyric: "I can be a ghost in your eardrum when you sleep:" "I think it's that feeling when someone gets stuck in your memory," she said. "And you can still hear that person, though they're not talking. That's what that feeling is."