"When we set out on this record it was Larry who came up with the plan not to have a plan. He put up this idea that wouldn’t it be great just to make music for its own sake, not for the purpose of a live show or on album but just to see what we’re capable of.."
- Bono, September 2008, talking on the upcoming album
The lyric "3:33 when the numbers fell off the clock face" from Unknown Caller is a reference to the Bible verse Jeremiah 33:3. Bono refers to it as "God's phone number".