"I thought 'pop' was a term of abuse, it seemed sort of insulting and lightweight. I didn't realise how cool it was. Because some of the best music does have a lightweight quality, it has a kind of oxygen in it, which is not to say it's emotionally shallow. We've had to get the brightly coloured wrapping paper right, because what's underneath is not so sweet." - Bono describing the difference between the "surface" of the songs to "what lies beneath".