A number of the tracks on Breath In. Breath Out. were written in the light of Hilary Duff's separation from husband Mike Comrie. This uplifting song is about finding the courage to let go of someone even when you're scared of what's to come. "I had been on my own for about four months and it's hard, but I also found a lot of strength and realized that I could handle it," Duff said. "It's a song about being ready to move on, whether it's with a partner or a friend. You have to be brave in a relationship."
"(What's So Funny 'Bout) Peace, Love, and Understanding" was written by Nick Lowe in 1974. The original version with his group Brinsley Schwarz was kind of somber, but Elvis Costello made it a classic with his 1978 uptempo take.