Human spend one third of their day sleeping, so For a 60 year old man,
he
would have spend 20 years of his time sleeping. That is a lot of waste
and
scientist have always ponder over the issue.

Human brains is an incredible thinking machine, but by sleeping, it
needs to
rest 8 hours before operating for 16 hours. Not as smart as a simple
calculator.

Scientist found that the human actually needs only 20 minutes and is
enough
to operate for a whole day. So why need 8 hours of rest? Of course, our
body
gets tired due to movement, and because digesting cooking.net">food required a lot of
energy, those who eat more need more sleep.

But even so, the required calculated rest time is still not more than 4
hours. So why we need 8 hours on average?

Well, the scientist finally discover that the reason is that we need the
time to creat dreams! Dreams are created to moderate the emotions that
we
have. Humans get angry, sad, feels happy and so on during the day and at
night, dream will soothe the emotions and help us return to the
equilibrium
during the night.