Bono is credited as the sole lyricist for eight of the ten songs, while the Edge received sole credit for "Numb". The duo share credits for the lyrics to "Dirty Day". Technology is a common theme on "Zooropa", inspired by the group's experiences on the Zoo TV Tour. Jon Pareles wrote that the songs are about how "media messages infect characters' souls", while music journalist David Browne said the songs are concerned with "emotional fracturing in the techno-tronic age". Critic Robert Hilburn interpreted the album as U2 probing into what they saw as the "disillusionment of the modern age".