Each and every living creature on this planet is dependant upon outside resources in order to survive. For instance, all animals need food to live. Most humans on the other hand, rely on others to produce food. We are no longer the hunters and the gatherers - we are consumers. This interdependency for the most part works.
Most people buy their food instead of foraging for food themselves.
Of course, buying food means that we must have money. And in order to have money, most of us need a job. Thus starts the vicious circle that has gotten most of us removed from the basics of being self-sufficient. Besides food, we need other things too - water, shelter and warmth. Again, most people today rely on outside resources to provide these things.