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
Sea otters hold hands while sleeping so they don’t drift away from each other.
104
You forget 90% of your dreams.
256
Lack of water is the #1 trigger of daytime fatigue.
148
The human brain is more active during sleep than during the day.
28
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
The average person falls asleep in seven minutes.
115