Well, there are two interpretations that seem official, the diary with the deluxe edition says that it was about a possitive view in long distance relationships, and Hayley once said that the band was feeling gratefult for being able to stand together "no one is as lucky as us", they almost broke because Hayley seemed to get all the attention.

I dedicated it to my boyfriend... Because he had to tell me how did he got so into my heart in a very little time and withouth making a single sound. I love him so much...
Also I spend vacations in a little town, and is almost two months away from him...