this may seem like an odd question, but is it possible for someone not to dream? from what i understand, dreaming is essential for keeping us alive. i know there are people who don't remember their dreams (i used to be the same way as a very young child before i started experiencing daily nightmares) -- i wish i were one of them again. <laugh>
Yep! I've a friend who did this - it's a side effect of a form of sleeping called Polyphasic sleep.
What the individual does is take broken down naps that usually aren't any longer than half an hour at most, and do this at a course of several times a day until they meet their desired amount.
What happens, as jillio stated, is that the REM (rapid eye movement) stage in your sleep is what causes you to have dreams -- but if you were to wake up prior to the REM stage in sleep, you would never have had a dream at all - some people experience a full night's rest in a pre-REM nap, in just 15 minutes.
When you wake up during the REM process, if you did not get enough sleep, often you'll feel tired or grumpy/ go back to bed etc.
One side effect of polyphasic sleeping is no REM obviously, so no dreams. The positive is that this schedule can accommodate someone who is on a very tight agenda everyday.
But my friend who did this, said sometime he experienced white flashes in his eyes like they were burning.
Anyways back to sleep discussion.. Often times I notice I die a lot in my dreams, just about every dream I die in, probably a 1 in 4 dreams it happens - I am always alive but dead in my dream. I continue to observe the scene in third person until the remainder of the dream, or appear somewhere else alive again in a different situation.
I honestly wonder what's going on.