Throw It In: When the band were recording for Insomniac, they were working on one song called "Stuck With Me", and another, yet-untitled song. Then someone at the studio mistakenly labeled a recording of the untitled song as "Stuck With Me", and the band decided to make that the new title - the song that was originally going to be "Stuck With Me" was released as a B-Side under the title "Do Dah Dah". As a result, they have one song with the Non-Appearing Title of "Stuck With Me", and another that has the line "You're stuck with me" in the chorus, but is called something else.
What Could Have Been: Cigarettes and Valentines, the follow-up to Warning that was supposed to be a return to Green Day's old sound. They recorded the entire album in 2003, but the master tapes were stolen before they could release it. Instead of rerecording everything, they decided to write an entirely new album, which became American Idiot.
They've been playing some of the songs from the album on the 21st Century Breakdown tour. The title track was featured on the live album Awesome As Fuck. It sounds like it would be right at home on Kerplunk or Dookie.
When Tim Armstrong was forming Rancid he asked Billie Joe to audition for the band. Billie Joe said no, as Green Day already had a few albums under their belt and were on the verge of becoming huge.