dream /dr:m/n

>asleep< [C] a series of thoughts, images and feelings that you experience when you are asleep           

                                    -- Longman Dictionary of contemporary English

To understand the reason WHY we dream, it is advised to first know Why we SLEEP and what " REM sleep " is.

" REM sleep" is a short term for " Rapid Eye Movement Sleep ".  It the the time when  we are about to enter our dreams but what are we are actually physically do is blinking and blinking and blinking...

Why do we sleep?

There are many assumptions of why we sleep.  The most common ones are for restoration and adaptation.  YES!  They are perfectly correct!

Restoration - Imagine how much work you have done today.  How tiring!  Sleep assists our body to fill up energy from the time when we are active.  Moreover, many always get easily irritated when they don't get enough sleep.  However, if they are lack of REM sleep for a few days, but still get a period of unperturbed sleep afterwards, they will enter " REM rebound ", which means the durability of REM sleep will be extra long than usual when it happens.  So you may ask, why bother to have more REM sleep?

Sleep, even REM sleep is very important to us.  It is the key component for good memory and learning.

Adaptation - It is a form of protection for many animals.  It is apt when daytime is their " survival of fitness " time, they need to conserve energy, prevent themselves from getting any harm.  Therefore, those that widely act as preys for predators attain the least amount of sleep.

Ok, so, why do we dream?

There are basically two main reasons on why we dream - physiologically and psychologically.

Physiologically - Our brain is exercised throughout the day by the brain waves we got and the messages sent out by the billions of brain cells for our thinking, acting, digestion etc.  Dreams, here then help exercise these " routes " that go between the brain cells.  In addition, the waves received by " REM sleep " are replacements for brain waves which are necessary for brain functioning.

Psychologically - There are many worries from work and problems unsolved that are left over from the day.  Dreams help providing spaces for yourself to obtain a calm and peaceful mind, in preparation for facing other troubles in real life.  They may also act as forerunners for any surprising incidents that one may or may or expect later on.

control of our brain about our skull major parts of our brain different views of our brain why do we dream? what about nightmares? what about recurring dreams? how to remember our dreams? what do my dreams mean? what about televisions? air conditioners? light bulbs? telephones? clocks? computers?  refrigerators? microwave ovens? Chinese culture? who are the authors?