Bono's mother, Iris Hewson, died in 1974 when the singer was 14 after suffering a brain aneurysm at her own father's funeral. He recounts on this song how the loss of his mother at such a young age shaped his life. "Forty years ago, my mother fell at her own father's funeral, and I never spoke with her again," he told Rolling Stone. "Rage always follows grief, and I had a lot of it, and I still have, but I channeled it into music and I still do. I have very few memories of my mother, and I put a few of them in a song called 'Iris.'"
Bono penned two songs in the early 1980s about the passing of his mother, "I Will Follow" and "Tomorrow." The 1997 Pop track "Mofo" also contains references to her.
The song contains a name-check for Kraftwerk's Man Machine album ("It was you made me your man/Machine"). Bono explained to Dave Fanning during a RTE Songs of Innocence special: "My mother died just as I was discovering girls. One of the girls I was discovering was Ali... she arrived at Mount Temple in the same month. The first lover's gift I gave Ali was a Kraftwerk album called Man Machine. So I referred to that."
Songs Of Innocence was released, by sheer coincidence, forty years to the day that Iris died. Said Bono: "Sometimes the things that have the most powerful influence over you are from way back. You're looking at the night sky and those beautiful stars - a lot of them are gone, even though you're still in their light. The idea that [Songs of Innocence] went out the same day, 40 years after she left us, is kind of magic."