1We spend a third of our lives doing it,
2yet we still don't completely understand this bizarre ritual we carry out each night.
3You lie down, your body goes unconscious,
4you see the weirdest pictures in your head,
5and then wake up, only to repeat the whole process the next day.
6Sleep is funny, and here's the proof:
7Like I said, you spend a third of your life off in dreamland,
8that's about 25 years if you were doing the math.
9We also spend about seven years of our lifetime trying to fall asleep.
10Everybody thinks you need eight hours of shut-eye each night,
11but your sleep hour requirement changes throughout your life.
12Children need 10 to 12 hours,
13teens need 8 to 11,
14adults 7 to 8 hours,
15and seniors are fine with six to seven hours.
16Now, good sleep is necessary for effective work and productivity,
17but good doesn't necessarily mean long.
18Some famous historical figures slept very little,
19from two to four hours,
20and this didn't prevent them from doing great things:
21Da Vinci, Franklin, Tesla, Churchill.
22And that's not all.
23There's a sleep mutation that allows a person to sleep just 2 to 6 hours
24and not experience any side effects.
25Now, if you have a dog or cat,
26then you might have noticed that they make funny sounds while they're sleeping.
27Yes, they do dream,
28and experts aren't quite sure why or what they see.
29My dog Riley even barks in his sleep.
30Temperature is a critical part of sleep and possibly dreams.
31If your room is too cold or hot, it can trigger nightmares,
32like you're in a cramped space or a fire.
33Some great discoveries were found thanks to dreams.
34For example, Mendeleev created the periodic table after he dreamed about it.
35This happens because our brain processes and analyzes all the events we experience throughout the day.
36Many experts believe this is why we dream in the first place.
37By the way, I love hearing dream stories.
38What's one dream you remember the most,
39or maybe have on a regular basis?
40Let me know down in the comments.
41And onto that weird sudden twitch your body might do as you're falling asleep,
42this happens because the brain sends impulses to the muscles.
43It's called a hypnic jerk.
44But why does the brain do it?
45Nobody knows for sure.
46Our brain shuts off all our muscles when we sleep.
47This is so that you don't run away in real life as you're dreaming about running away from some pursuer.
48But the brain doesn't shut off the eye muscles,
49which is why your eyes can move,
50and they do during the deepest part of sleep,
51a stage called REM or rapid eye movement.
52But what if your brain wakes up, and your body muscles are still disabled?
53This condition is called sleep paralysis.
54Many people have experienced it at least once in their life,
55and those same people say it's far from pleasant.
56Sleep and reality are mixed in this state,
57and individuals can see hallucinations.
58Babies dream in the womb,
59but there are no visual images in these dreams,
60only tactile and auditory sensations.
61Our spine relaxes and stretches when we sleep,
62meaning you can be a wee bit taller in the morning than in the evening.
63People sleep under blankets not only for warmth,
64though that does help.
65It's also psychological.
66We relax better thanks to the blanket's touch, even if it's heavy.
67That slightest bit of pressure on our bodies soothes the nervous system,
68much like a hug.
69We also feel more protected when we sleep under the covers.
70A body out in the open makes a person feel uncomfortable and vulnerable,
71especially when you're about to let your guard down and go to sleep.
72And, well, the blanket thing is just a custom,
73even if you don't feel like you need it,
74it feels weird to sleep without it.
75Japan and South Korea get the least sleep on Earth,
76less than six hours.
77New Zealand gets the most, a whopping eight hours,
78one of the few places getting the recommended amount.
79College students might not believe me,
80but pulling all-nighters cramming for an exam won't help your grade.
81If you're gonna do that,
82do it a couple of days before the big test day.
83The night before, get good sleep.
84It helps you retain learned information.
85Nobody knows for sure what causes déjà vu.
86One of the theories is associated with sleep.
87Even though it translates from French as "already seen,"
88you likely dream something but forgot about it by the morning.
89Then, in reality, you see those events that are a bit like the forgotten dream.
90Have you ever had déjà vu?
91A lot of animals, like horses and zebras, sleep while standing.
92Their body has evolved to pull this off
93so they can run away from danger at any moment.
94Some birds, the albatross as an example, can sleep while flying.
95There's a whole laundry list of animals
96dolphins, manatees, penguins, and crocodiles, to name a few,
97that sleep with one eye open.
98It's possible because half of their brains are working and watching the situation around,
99while the other half sleeps.
100Some people not only snore during sleep
101but can also grind, gnash, or clench their teeth.
102This is called bruxism.
103Like a lot of things connected to the world of sleep,
104nobody knows the exact causes of this phenomenon.
105Sleep is as vital to humans as food and water are.
106A healthy person will live longer without food than without sleep.
107It seems obvious that we need to sleep
108so that all our body's bits can refresh themselves,
109but no one has fully figured out all the effects sleep has on the body
110only that we need it, and we don't do well at all without it.
111One thing's for sure: our body accumulates energy during sleep.
112If you don't sleep for a long time,
113then the body looks for this energy in food.
114Not surprisingly, lack of sleep often leads to weight gain.
115Sleepwalking is another mystery we haven't figured out yet,
116but there are plenty of misconceptions surrounding it.
117You might imagine a sleepwalker with their arms extended out in front of them like a zombie,
118but that's just not the case.
119You often can't even recognize if a person is sleepwalking.
120And waking a sleepwalker won't give them a heart attack,
121but it probably will give them a shock,
122and they might try to fight you.
123It's much better to gently guide a sleepwalker back to bed without waking them,
124if you can.
125Many people claim that they don't dream at all,
126but they likely just forget the dreams they do have.
127If you want to remember your dreams,
128then put a notebook or a voice recorder next to the bed.
129As soon as you wake up, immediately get to writing or recording.
130The first 90 seconds after waking up are ideal.
131It might take some practice,
132but you will start remembering more and more of your bizarre brain movies.
133If you do remember your dreams,
134how many do you think you have a night?
135One big long epic movie?
136Nope.
137It's more like four to six of them each night,
138and your dreams get longer throughout the night.
139It's the final one you're probably recalling.
140Before there were alarm clocks,
141people had all kinds of ways to wake up.
142Some got up with the sun at the crack of dawn,
143others depended on their rooster to wake them,
144and in more populated areas,
145it was thanks to the ringing of the city tower.
146There was also a special profession called a "knocker-upper."
147This probably not-very-popular fella
148would walk among houses in the morning
149and knock on bedroom windows to wake people up for work.
150Lullabies - how do they work on babies so well?
151Well, imagine you're a baby again.
152You've had a busy day discovering new things in this world,
153all kinds of smells, sounds, materials.
154The day you found your toes? It was a particularly busy one.
155It's hard to fall asleep at the end of the day
156when your brain is struggling to analyze such a massive storm of new information.
157But when you hear a lullaby,
158your brain can concentrate on one thing
159that soothing, hypnotic voice.
160Your head clears, you feel at peace,
161and sleep soon follows.
162On that note, I'm getting kind of sleepy myself.