Now that I drive to work, sometimes I wonder: what if an emergency happens? A car hits me from behind, or someone changes into my lane... this never happens, so how can I be prepared for it? Are my dreams helping out?
For centuries people people have wondered about the meaning of dreams. Some time ago I decided that the likely primary purpose of dreaming is to train us for potential future situations: a sort of virtual reality where the brain creates a random situation, we react to it in the dream state, and then the brain attempts to predict the outcome. By doing this every night, we learn, while asleep, how to react to waking situations before they ever happen.
This article I just found lends credence to my pet theory. Of course, it is widely reported that we learn better if we sleep after studying. So perhaps dreams also exist to give the brain a chance to examine what has recently happened, and make better sense of it.