i feel like this song could be about the problem of trying to really know someone. when she says "outside my head i cast a shadow" she's talking about the person that other people see in her, but she's "not someone who's seen this side of me". she says "i can turn to you and ask you what you saw", to know how she appears to others, but it still doesn't give her any understanding of herself. i feel like the last lines are saying that she's stuck living inside her head, and is "dying for a way out" of it.
i feel like this song could be about the problem of trying to really know someone. when she says "outside my head i cast a shadow" she's talking about the person that other people see in her, but she's "not someone who's seen this side of me". she says "i can turn to you and ask you what you saw", to know how she appears to others, but it still doesn't give her any understanding of herself. i feel like the last lines are saying that she's stuck living inside her head, and is "dying for a way out" of it.