The human brain is more active during sleep than during the day.
28
47% of people have a nightmare at least once a month.
186
In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
People who sleep late have more mental stamina and can outperform early risers.
33
You burn more calories sleeping than you do watching television.
348
Some people have a "natural alarm clock" allowing them to wake up when they want. This is actually caused by a burst of the stress hormone adrenocorticotropin.
15