"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."
During the ZooTV Tour, U2 wanted to play a show in Sarajevo. Due to logistical problems they couldn't play there during that tour so instead they created a video uplink to Sarajevo during most ZooTV shows. On the Popmart Tour, they played their first (and so far only) show in Sarajevo, finally fulfilling that vision.