Why do we have to sleep?

Question

Why do we have to sleep?

Answer 1

to recharge our batteries.

even computers need to be turned off sometimes.

Answer 2

To recharge.

Answer 3

so that...

Answer 4

so are body can recharge  

Answer 5

No one is entirely sure why this is. The main thing that is known is that if we don't, we hallucinate, and eventually die.

One theory is the theory of evolution which states that those who slept during the night saved energy to find food during the day, and were hidden from nocturnal predators, so they survived to pass on their genes.

Another theory is the theory of restoration, which states that sleep is used to restore nerve cells in the brain, repair muscle tissue, and for growth.