Katy wrote this song about an ex who broke her heart. She told The Sun: "'Go Away' is about one person, though I've never asked him if he knows it's about him. That would be terrifying. It's hard enough to put it out there how you are feeling without them knowing, but I guess I can't hide all the time."
Who writes a song about a name they found in a phone book? That's just one of the everyday things these guys find to sing about. Anything in their field of vision or general scope of knowledge is fair game. If you cross paths with them, so are you.