I think that this song is about, a relationship coming to a close. She doesn't really want it to end, but shes accepting it. She wants it to be easy and them to leave on a good note.
But she will always have him in her heart, and she knows that deep down that he is special- that he shines brightest. And she want him to know that too.
I really realllyyy love this song. Paramore-Rockkk: D