Pack a latin version of the graduale and as much church music as I could cram in a bag. If the bag wasn't coming with me I'd read up on the survivalist websites. Making a compass, that sort of thing.

The thing I'd be most worried about is dental hygiene. How do you look after yourself if you don't have a toothbrush and floss? I suppose there'd be less white sugar, which would help. What food you could get would taste bland and generally be awful.