I didn't take the "everyone will die eventually" theme from it. As an underlying theme I saw that there is still good no matter what evil is in the world. Tommy Lee Jones and the sheriff from the other town are talking and the sheriff mentions that when kids stop saying "sir", it's the beginning of the end and all will follow but after the accident, the two boys stop and they're extremely polite to Anton calling him "sir" and the one giving the short off his back.
That's just one but the movie is awesome. Love it love it.