Incest?
Am I the only one who was a bit perplexed when Neil and Madeleine (brother and sister) MADE OUT towards the end of the movie??? And she had her hands all over him? That was no regular brother/sister affection.
So maybe thats why he was so very intent on finding her? Because she was his true love? And she was still a virgin b/c she only longed for her brother? It was just so awkward.