Who would have thought there was more to sleeping than a blanket a pair of good underpants and maybe a pillow (for those who like support on their necks).
A bunch of psychologists decided to watch people sleep, and thus the truths about sleep and our consciousness came to being.
Sleeping is a multistage process, five in total. Ranging from being on the brink of being asleep to being in deep slumbers. The interesting thing is we fluctuate between these stages while sleeping.
People experience sleep disorders, like insomnia where they are unable to sleep, or Narcolepsy where people just fall asleep suddenly.
Dreams are an important part of sleep, and various ideas express their purpose. Freud described them as "Repressed Uncontentious Wishes" while the Activation-Synthesis Theory suggests that dreams are merely from brain activity while sleeping, so the signals are incomplete.
Between the basic understanding of the human sleep process, to the various disorders effecting beneficial rest, chapter 5 of our consciousness should be a eye opening adventure.