On the bright side, if the infrastructure of the world collapses and we descend once again into tribalism, or if there is a cataclysmic annihilation of humankind and you're one of the survivors, you don't have to worry about getting appendicitis and dying!
Play Games
As for wasting time, I fully reccommend creating an account on
Kongregate and playing flash games to your heart's content. They have a huge range of games, and a lot of badges/achievements for the more popular ones, which quickly leads into a "just... one more badge..." mentality :P
Make Games!
If you're looking for something remotely productive to do and you've always wanted to learn how to program,
Code Academy just recently started a load of online courses. At the moment they have 13 courses in Javascript, ranging from the most basic of basics to building simple games and tutorials in the more complex structures. If you're hesitant - coding is actually quite simple, once you get your head about what it looks like, and contrary to non-computer scientist belief, it's actually quite fun!