The idea for the song came from guitarist Mark Sheehan recounting to his bandmates a conversation that he'd had with his wife. Singer Danny O'Donoghue explained to entertainment.ie
: " It was an innocent conversation but Mark being Mr. Galileo himself was explaining the sun, moon and the stars and how everything works in the world in the way that a man would. In doing so, it moved on to chemical reactions in the brain, how she's in love with him and he's in love with her. You could see her face going down, he's pulling apart every detail of why they were in love and breaking it all down to a science. She said then 'what about faith, what about hope, what about love? You won't find anything about those things in science books.'"
O'Donoghue continued: "He came in the next day and he was like 'you'll never guess what I said last night.' I kind of stemmed from that, and the more that you mess around with science and faith it is two worlds combining. I think people will look at an Irish band and say that they're talking about science and they're talking about religion. I like that because that is so opposite to what this band is about. We're not about politics and we're not about religion, those are subjects we stay away from all the time. It's literally a love song and it's about the ebb and flow between a male and a female."