It's late at night and you are getting very, very sleepy. You hit the bed and your brain signals your body: it's lights out for you. But as soon as you go to sleep, this mysterious phenomenon hits you out of nowhere and you are lost in the world of dreams. In the morning, you don't even remember what you dreamed about last night.
Have you ever wondered why we usually forget our dreams?
When we go to sleep at night our brain goes on a strange sleep roller coaster, passing through different sleep stages over and over, so in a typical 8-hour sleep, the brain passes through these stages four to five times.
Have you ever watched other people or even your pet sleeping? You must have noticed them twitching their eyelids. The twitching only happens when we are in the deepest stage of our sleep called "REM" or "Rapid Eye Movement" and it is during this stage that most dreams occur. There used to be a theory stating that we dream only during the REM stage, but researchers have proved this theory wrong and now most experts agree that dreams can occur during any sleep stage.
One question that has no proper answer is, 'why do we dream?' Scientists have been trying to solve this mystery but still haven't reached any conclusion. Some believe that dreams are a form of problem-solving, while some believe that we process what we experience during the day, and others believe that dreams are a bodily function. But, what we can all agree on is the fact that we all dream.
Sometimes, if not most of the time, we forget what we dreamt about. The reason is due to neurochemical conditions in our brain which usually occur during REM sleep.
The quality of our sleep determines whether or not we remember our dreams. For most of us, dreams are easily forgotten once we wake up and that happens because we do not consolidate our dreams. Our mind needs to transfer the dreams from short-term memory to long-term memory, and unless we do it immediately after waking up, the dream just disappears.
There are few theories surrounding it. One of them is that our brain's neuro-chemicals work differently when we are asleep than when we are awake, so they do not allow us to consolidate our memory. Another possibility is that we aren't able to pay attention to our dreams while we are sleeping.
When we have a long REM sleep period and wake up once the REM sleep period is over, we find that dreams don't increase in length and whatever it was we were dreaming about just vanishes into thin air. We simply forget what was happening.
We are amazing at forgetting nonessentials and tend to recall only those things that have an emotional significance. Most dreams just vanish, but some do tend to linger on. The more impressive our dream is, the higher our chances are to remember it.