Everybody loves a good sleep

Why do we “sleep tight”? 12 sleep-related idioms explained


Published on March 24, 2026


Image: Alexander Possingham

Have you ever uttered the words "sleep tight" or "hit the hay" before going to bed? These phrases have existed for ages, but their meanings and origins are not always apparent. Some are directly related to sleeping, while others are metaphors for entirely different things. Take a look at 12 of these idioms. Do you use any of them?

1

Sleep tight

Image: Sinitta Leunen

"Sleep tight" is a phrase most people know from the bedtime verse: "Sleep tight, don’t let the bedbugs bite". It’s often claimed to come from the old practice of tightly tying ropes on bed frames to keep mattresses firm and comfortable. This helped prevent sagging and made for a better night’s sleep.

In older English, "tight" simply meant "soundly" or "well", making "sleep tight" a wish for a good night’s sleep.

2

Hit the hay

Image: Simon Infanger

"Hit the hay" dates back to the late 19th or early 20th century and is often linked to the practice of stuffing hay into sacks or mattresses for sleeping, which is also commonly cited as an explanation for the phrase "hit the sack."

Another theory suggests that farm workers sometimes slept directly in haystacks, making "hay" a stand-in for "bed." Because "hit the hay" appears in print slightly earlier than "hit the sack," some believe it may have come first.

3

To sleep like a baby

Image: hessam nabavi

Anyone who has had a newborn knows how strange the phrase "sleep like a baby" sounds: babies wake up often and cry! Yet, the idiom means to sleep peacefully and deeply.

The idea is that when babies do sleep, they’re completely at ease, with no worries to disturb them. That peaceful, undisturbed state is what the phrase refers to, even if it doesn’t match the full reality.

4

Let sleeping dogs lie

Image: Irina

"Let sleeping dogs lie" might sound odd at first, but its meaning becomes clear with a bit of explanation. It’s a warning to leave past issues alone, especially sensitive ones.

The phrase compares old disputes to sleeping dogs: if you wake them, they might react aggressively. Similarly, revisiting old problems can stir up trouble best left alone.

5

A catnap

Image: Aleksandar Cvetanovic

A "catnap" is a short, light nap, usually under 30 minutes, during which you do not enter deep sleep. Studies suggest that even a 10-minute nap can be refreshing, sometimes nearly as effective as a longer one, though the ideal length varies by person.

The term comes from cats’ daytime sleep habits. Since wild cats had to stay alert for danger, they took quick, light naps. Today’s cats do the same, snoozing lightly throughout the day, just like a good catnap.

6

Wrong side of the bed

Image: Greg Pappas

"Waking up on the wrong side of the bed" means starting the day in a bad mood. The phrase comes from an old Roman superstition.

Romans, including Augustus Caesar, believed getting up on the left, or sinister, side brought bad luck. As a result, the "wrong side" was more than just a bad mood starter; it was thought to be a bad omen.

7

Sleep like a log

Image: Shane

To "sleep like a log" means to sleep deeply and without moving, like a heavy log lying still. It’s a common way to describe a peaceful, undisturbed night.

The origin of the phrase is unclear, but some link it to lumberjacks who slept soundly after hard work. Others connect it to the similarity between snoring and the sound of sawing.

8

Counting sheep

Image: Annie Spratt

"Counting sheep" means imagining sheep jumping over a fence, one by one, to help you fall asleep. It’s a classic mental trick to quiet the mind.

The phrase likely comes from shepherds who counted their flocks at night to ensure none were missing, a repetitive and calming routine before bed.

9

Lose sleep over something or somebody

Image: Михаил Калегин

The idiom "to lose sleep over something" means to worry about something to the point that it becomes difficult to sleep, or to be so concerned that it disrupts one’s rest.

While the exact origin of the phrase is difficult to pinpoint, it likely evolved from the idea that intense worry and stress can interfere with the body's natural sleep cycle.

10

Do something in your sleep

Image: Nubelson Fernandes

To "do something in your sleep" means to do something very easily and effortlessly, usually because you have done it so many times that it's become second nature. It's a metaphorical way of saying that you are so proficient at a task that you don't even have to think about it, as if you could do it while unconscious.

11

Sleep with one eye open

Image: Jamie Street

"Sleep with one eye open" means staying alert or cautious, especially in risky situations. It suggests being ready for trouble, even while resting.

The phrase is often linked to animals such as dolphins and certain birds that can literally sleep with part of their brain awake to remain safe.

12

Sleep around the clock

Image: Vin Jack

To "sleep around the clock" means to sleep for many hours without waking. It often happens when you're exhausted or feeling unwell. It’s a way in which the body tries to recover energy.


We just know that we know nothing

12 facts that people often get wrong


Published on March 24, 2026


Image: Andrea De Santis

No one can claim to know everything, but most people go through life confident about certain things. However, some of these widely held beliefs are not actually correct, despite their popularity. Let’s have a look at some "facts" you might have gotten wrong!

1

Insects are animals

Image: Syed Ali

The idea that insects—particularly mosquitoes—are not animals is widespread, but it’s also incorrect. In fact, insects are the most diverse group within the Animal kingdom, with more than a million species described and representing more than half of the animal population of the planet.

2

Tomatoes (and many other "veggies") are actually fruits

Image: Heder Neves

The mistake comes from not considering that "fruit" is not only a culinary term but also a botanical one. Botanically, a fruit is the part of a plant that develops from a flower and contains seeds. This makes tomatoes, peppers, cucumbers, eggplants, and many other foods that we call vegetables actually fruits in the scientific sense.

3

Russia is both in Europe and Asia

Image: Michael Parulava

Countries have a political delimitation, while continents are divided according to geographical criteria. The Russian Federation is the largest country on Earth, bordering fourteen other countries and extending across eleven time zones. It spans across a good part of Eastern Europe, but also across the Ural mountains—one of the recognized borders between Europe and Asia—and stretches deep into northern Asia.

4

The flu is not caused by cold weather

Image: Towfiqu barbhuiya

While cold weather isn’t harmless, it is not the direct cause of illnesses like the flu, which are caused by viruses. In colder months, people tend to spend more time indoors and often avoid ventilating rooms, creating conditions that make it easier for viruses to spread and cause illness.

5

Bats are not blind

Image: Riizz

Bats might not prefer to be out during bright daylight, but this does not mean that they are blind. In fact, many species have excellent eyesight, though it is adapted to low-light or nighttime conditions. On top of that, bats also use echolocation, which allows them to navigate and hunt with remarkable precision in complete darkness.

6

You don't need to wait 24 hours to file a missing persons report

Image: Volodymyr Hryshchenko

The belief that you must wait a full day before reporting someone missing is a myth popularized by movies and TV shows. In reality, the law does not require a waiting period. In fact, law enforcement agencies stress that the first 24 hours are often the most critical, so a missing person should be reported immediately.

7

The Great Wall of China can’t be seen from space

Image: NASA

Some man-made structures are visible from space without magnification, but despite popular belief, the Great Wall of China is not one of them. While it is quite long, being over 13,000 miles long, it is relatively narrow, and its earthy colors blend in with the surrounding landscape, making it nearly impossible to spot with the naked eye from orbit.

8

Mount Everest is not the tallest mountain on Earth

Image: Andreas Gäbler

This one is tricky: Mount Everest is the highest mountain on Earth (29,032 feet)… if you measure the distance from sea level to peak. For the actual tallest mountain, the answer might vary depending on how you measure. Measured from base to summit, Mauna Kea in Hawaii is the tallest at 33,474 feet—though much of it is underwater. Mount McKinley (Denali) in Alaska rises about 18,000 feet from its base to the peak, making it the tallest mountain entirely above sea level. And Ecuador’s Mount Chimborazo, while shorter in height, is the farthest point on Earth from the planet’s center due to the equatorial bulge.

9

The Northern and Southern Hemispheres have opposite seasons

Image: Kyle Glenn

The Earth is tilted on an axis, which causes the amount of sunlight each hemisphere receives to change as it orbits the Sun. Because of this tilt, when the Northern Hemisphere is tilted toward the Sun and experiences summer, the Southern Hemisphere is tilted away and experiences winter—and vice versa. This is why the Southern Hemisphere celebrates Christmas during summer.

10

It’s not dangerous to wake a sleepwalking person

Image: Kate Stone Matheson

Standard medical advice is to gently guide a sleepwalker back to bed rather than waking them, but not because waking them is inherently dangerous. People tend to sleepwalk during deep sleep, so waking them up might startle them or cause confusion and disorientation.

11

Shaving won’t make your hair grow thicker

Image: Supply

Hair color and thickness are determined by genetics, not by shaving. Hair naturally gets thin at the ends, so when you shave it, the hair shaft appears to be thicker and darker because of the blunt cut. But it's just an optical illusion; the natural size of the shaft remains unchanged.

12

Coffee won’t dehydrate you

Image: Mike Kenneally

Coffee is a natural diuretic, meaning it can increase trips to the bathroom. However, the water in brewed coffee still contributes to your hydration and offsets its mild diuretic effect. If you consume coffee in moderation—3 to 5 cups a day, depending on your tolerance—you should be alright. However, drinking extra water on the side is never a bad idea.

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quiddity

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