Good Planning or Going Overboard?

I'm all for good planning, I'm all for being prepared for anything, and I'm all for sustainability. However, I wonder if it's possible to be too paranoid. Just how far is too far to expect one to be able to maintain sustainability in the city and why should it suddenly be my personal responsibility to arrange survival means for our family in the event of a social collapse?

I actually can do quite a lot right now. However, a breakdown in society may render any preparations pointless, as was pointed out to me by my dear other half, so what's the point in the first place? Personally, after looking carefully backward, my first suggestion was to establish close ties with neighbors in the community. A group of people working together stands a much stronger chance for survival than a single family. Look at the Amish, they've maintained sustainability for centuries.

For our family it would mean finding a source for water, the one commodity that would become very quickly in short supply. We have small animals that could be used for meat and eggs. We have fruit trees and can plant a garden. Milk and flour would be difficult to replace, though flour is cheap at the moment and dried milk could be gotten.

So there is a lot I could do in the event that supplies became difficult to locate. Not everything would be so easy however, we use electricity for both heat and cooking and artificial light sources would be difficult as wax sources are rare.