why???

Why we need sleep
Sleep helps you to restore and rejuvenate many body functions:

• Memory and learning – Sleep seems to organize memories, as well as help you to recover memories. After you learn something new, sleep may solidify the learning in your brain.
• Mood enhancement and social behaviors - The parts of the brain that control emotions, decision-making, and social interactions slow down dramatically during sleep, allowing optimal performance when awake. REM sleep seems especially important for a good mood during the day. Tired people are often cranky and easily frustrated.
• Nervous system – Some sleep experts suggest that neurons used during the day repair themselves during sleep. When we experience sleep deprivation, neurons are unable to perform effectively, and the nervous system is impaired.
• Immune system – Without adequate sleep, the immune system becomes weak, and the body becomes more vulnerable to infection and disease.
• Growth and development – Growth hormones are released during sleep, and sleep is vital to proper physical and mental development.