The speaker of "Newborn Heart" is someone who wants to change. The person, who for the purpose of this explication will be referred to as a male, doesn't want to continue lying and taking the wrong paths in life, because even though he thinks that he knows what he wants, his choices cause more grief than they help him. He is a person who likes to have control over his life, and plans everything out in detail. However, even though he tries to dictate what will happen, it doesn't work. He still feels as if he is worthless. This could be because his idealistic attitude gives him an unrealistic expectation. He does, however, think that he has a saving grace, the person to whom he is speaking. (Again, for the sake of this explication, this person will be referred to as female.) He feels that her presence makes him a better person, and, when she is around, there is no need for the lies and false promises: to anyone, including himself. He is a different person.
Although it is possible that the speaker is talking to his love and that she is listening, it is also possible, and likely, that the entire song is an apostrophe, a literary device in which an absent entity is directly addressed. That would also make the song a soliloquy, where he is alone and speaking his thoughts aloud. Figurative language is also used. "Counting on a star." can refer to the actual act for counting stars, but "star" can also be a metaphor for a heavenly entity, or a higher power. Another metaphor is "taking all the wrong doors", which is comparing a door to a choice. Another device used in this piece is symbolism. The symbols used include light and windows. The light represents knowledge, and the window represents experience. Therefore, with the line "magnify the light that shines through my window" it can be interpreted that he feels that he gains more out of situations if they are with her.
The song can easily be related to Holden Caulfield.