"Dirty Day is a father and son song. 'It's a dirty day', was an expression my dad would use and there is a lot of him in there but it was also influenced by Charles Bukowski, the great American writer and drinker. The song is about a character who has walked out on his family and, years later, meets the son he's abandoned. It's not about my father but I used some of my dad's attitude in it."
did you know
U2 intended to release No Line on the Horizon in November 2008; after composing 50 to 60 songs, they postponed the release because they wanted to continue writing.