Bono holds a bottle of champagne

"The B-sides are really important. It's like they're more revealing. A lot of times we wrote them in the middle of the night, as we were recording them, usually being thrown out of studios. People would be knocking on the doors saying, 'You have to leave,' but we don't have a B-side. It's a bit like a photograph, like a polaroid. You didn't take that much care putting it together, but it captures a moment that tells a story." - Bono on the B-sides of the Best Of 1980-1990 album, 1998