The line
"You can't fly these wings,
You can't sleep in this box with me"
is the perfect line to take meaning from this song. He isn't doing anything with his life and she is trying to urge him, but can't, and when he is gone she can't go with him. She can't live his life for him how he should and it's killing him that he is becoming the death of her, so he has to leave to "save her".
The line "You can't fly these wings, You can't sleep in this box with me" is the perfect line to take meaning from this song. He isn't doing anything with his life and she is trying to urge him, but can't, and when he is gone she can't go with him. She can't live his life for him how he should and it's killing him that he is becoming the death of her, so he has to leave to "save her".