"Someday (I Will Understand)" was released as a single in Europe on August 21, 2005, off the bonus EP that came with the DVD for the reality show, Britney & Kevin: Chaotic. Britney wrote and composed the track on her piano before even knowing she was pregnant with her first child, Sean Preston. "I wrote 'Someday' two weeks before I found out I was pregnant," she said. "It's kinda like a prophecy... when you're pregnant, you're empowered." The Chaotic EP included the fan favorite and B-side, "Mona Lisa," which was also co-written by Britney.