This song is about the frustration of being left behind. It's almost like a toxic relationship, where a person completely took advantage of you without you realizing it, they drain you and leave you empty. And after they're done with you, they just leave. And you stay there, stranded and lost. But eventually the feeling of sadness and grief has to go away, so you finally decide to let the person go, until the last piece of memory is faded completely.