4 Answers

Read here...http://www.geekosystem.com/understanding-sleep/

yadu - we need to sleep to download all the stuff going on in our brains - sorting it and putting it into perspective, into compartments into the subconscious one example. Shakespeare says "sleep perchance to dream" and Carl Gustav Jung - Swiss psychiatrist, psychotherapist and analytical psychologist - is one of the best known contributors of Dream Analysis. Also of course need sleep for the physical body.    

Sleep is required to repair our bodies, both physically and mentally. Those who sleep very little, often have many health problems as they age. Sometimes, people brag about how little sleep they need and often they use drugs such as caffeine to maintain their "alertness". This is unhealthy according to health care professionals.

......it's the only way you can wake up...

Ducky

lol