...humans, perhaps uniquely, can generate mental models of our circumstances that enable us to anticipate future changes and concoct coping strategies. We use our working memory to hold mental representations of situations. We can envision a fantasized scenario and compare this image with a model of our current state. By doing so, we can simulate strategies to reduce the difference between where we are and where we want to wind up in the future, giving us a key evolutionary advantage. We might mentally rehearse ways to out-compete others, for instance, for a mate or a job promotion. The combination of consciousness, self-awareness, and explicit problem solving is what enables us to learn things not relevant to our evolutionary past.
—David C. Geary in Scientific American Mind. "Primal Brain in the Modern Classroom." September/October, 2011. Pages 45-49.
Note: for modern-day Christians, there is an out. In this parable (Matthew 6:31-33), Jesus said to seek his kingdom first, and your biological needs would then be met. Hence, as long as you place god above the mundane chore of planning, you may be okay.