Personally how I would interpret this song is that I think there's this guy, and he happens to love this girl. Although to him walking away is the hardest part. Not only because he loves her, but because whether or not she feels completely the same way, they don't agree that their relationship would work out in the end because of the distance between them. And since the lyrics referred to inches apart on a map, that implies that they live hundreds of miles away, and rely on their phonecalls with eachother and re-reading letters/texts from eachother just to be able to believe in the love that they share. Walking away's the hardest part because neither of them may want it, it's just what they feel would be nesseccary* because they don't in time feel for hurting the other because of distance or petty differences. That's what I believe this song is about, and I for one adore the song. And somewhat can relate to it.