Do you know Why do we awaken from sleep, because Everybody has strange experiences with sleep. Sometimes we can not wait to go to sleep and other times we just can’t seem to get to sleep. What actually wakes us up is something that scientists find hard to explain. When we go about thinking and seeing and feeling and carrying on mental activities of all sorts, we use up a lot of energy. So, the brain and other nerve centers need a rest.
Sleep clears away our tiredness and when we wake up we feel rested. The most probable reason is that while we are asleep our body still feels hungry, cold or even damp, or we may experience an emotion such as fear.
These feelings stimulate our brain and cause us to wakeup. Of course we may wake up simply because we have had enough sleep.