U2 in Portugal

"My earliest memory of waking up with a melody in my head was, you know, 8, 9, 10. I've always heard kind of melodies in my head. I remember standing under a piano at my grandmother's house, when the keys of the piano were higher than my head and kind of pressing down on the keys, and then hearing one note and then looking for another one to follow it, because you always -- you know, if you're a musician or if you're a songwriter, somehow when you hear one note, you hear another one." - Bono, 2002