dreamy

What function do dreams serve in evolutionary terms?

a warning
a reminder
a stubborn refusal to forget
a way of keeping past fear close?

terrible, terrible dreams.

http://www.epjournal.net/filestore/ep035978.pdf

"Threat Rehearsal
    When awoken abruptly from a terrifying nightmare, it is easy to understand the strength dream imagery has in generating both physiological and cognitive responses. In the case of a nightmare, heart rate is accelerated, sweating occurs, and a general feeling of fear and anxiety can extend for some time after the dream has finished (Mellman et al., 1985). Even though dreams are a form of mental representation, in the sense that perception is not tied to stimuli in the environment, they are generally experienced as real and the content is perceptually indistinguishable from waking perception (Freud, 1900).
     If merely imagining an event has the power to better prepare us for an actual event by physically activating comparable brain regions, then it should follow that the more realistic the simulation of events, the more the brain treats the information as real. Also, if this capacity to simulate an environment allows us to be optimally prepared to deal with challenges in a real environment, it should affect fitness and be naturally selected for across generations (Darwin, 1995). The threat-simulation hypothesis of dreaming argues that this is the purpose of dreams and the reason why dreaming has evolved (Revonsuo, 2000). It is suggested by this theory that dreams serve the purpose of allowing for the rehearsal of threatening scenarios in order to better prepare an individual for real-life."