Well as you can probably guess from the answers so far, there's no exact known right answer. There are lots of different theories. It may because dreaming is a process of the unconscious mind. Whether the unconscious is working out our conscious problems, or just pulling out random memories and images, when we wake up we become aware of our conscious environment and so put these back into our unconscious minds. Alternatively, our dreams sometimes work in metaphors, which explains why they are sometimes so apparently random. We forget them when we wake because our conscious minds can't understand them anyway. Another famous psychologist called Frued said that our dreams are actually our minds way of figuring out things that are too traumatic for our conscious minds to cope with. Hence its a self-defence mechanism for us to forget the dreams.
It's been proven in studies that we forget 90% of our dreams when we wake up. Dreams occur during a stage of sleep called rapid eye movement. We have sleep cycles in which REM sleep comes round every 90 minutes or so. We have dreams during most of these stages of REM sleep, usually you'll only be able to remember at most 1 dream a night, so you can see just how many dreams we actually forget.
It's been proven in studies that we forget 90% of our dreams when we wake up. Dreams occur during a stage of sleep called rapid eye movement. We have sleep cycles in which REM sleep comes round every 90 minutes or so. We have dreams during most of these stages of REM sleep, usually you'll only be able to remember at most 1 dream a night, so you can see just how many dreams we actually forget.
