Respuesta :
These lines say that the speaker is never going to give up on pursuing his beloved, however hard she rejects him. However, he doesn't seem to despair because of it. He almost thinks it is the world's natural order: while some were meant to love and pursue, others were meant to hate and reject. For him, each failure is only an impetus to keep trying. The fate's role in this situation is seen through expressions "while I am I, and you are you", and "must" - as if he can't help it but pursue her.
He will try to win her love for as long as they are both alive.