The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
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
47% of people have a nightmare at least once a month.
186
The human brain is more active during sleep than during the day.
28