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.


10 weird historical events that no one has been able to explain (yet)


Published on March 24, 2026


Image: Walters Art Museum, Public domain, via Wikimedia Commons

Who doesn't like a good mystery? And if the mystery isn’t a work of fiction but the result of a true story, even better! The great unsolved enigmas of history are absolutely fascinating. Some have been solved over time, but there are still many old secrets for which neither scientists nor historians have found an explanation—yet. Time-travel with us as we uncover 10 of the biggest historical mysteries that will probably never be cracked!

1

A ghost island

Image: Tanner, Henry S., Public domain, via Wikimedia Commons

Bermeja Island is mentioned in navigation texts written by European travelers and appears in cartography from the 16th to 19th centuries. Old maps place it off the north coast of the Yucatán Peninsula; however, multiple searches over the years have yielded no concrete evidence of its existence.

So, what happened to Isla Bermeja? Was it a cartographic error? Did it sink due to a tidal wave? Because of its geopolitical significance, some have even suggested that it was blown up by the CIA! A 2009 study by the Autonomous University of Mexico concluded that Isla Bermeja does not exist today, nor were any traces found at its supposed coordinates. Yet, it will forever remain a mystery that will surely keep many entertained.

2

The longest alien signal ever

Image: Credit: Big Ear Radio Observatory and North American AstroPhysical Observatory (NAAPO)., Public domain, via Wikimedia Commons

In 1977, Ohio State University’s Big Ear radio telescope, used in the search for extraterrestrial intelligence, detected a signal now known as the Wow! signal. While reviewing the data, astronomer Jerry R. Ehman noticed a sequence represented as "6EQUJ5." Baffled by the anomaly, he circled it and wrote "Wow!" in the margins.

The signal lasted 72 seconds and, unfortunately, has never been repeated. To this day, no one can fully explain the phenomenon, although some suggest it may have come from a man-made source. Still, the Wow! signal remains one of the strongest candidates for potential extraterrestrial contact ever detected.

3

The disappearance of an entire Inuit village

Image: Edward S. Curtis, Public domain, via Wikimedia Commons

How is it possible for an entire village to vanish without a trace? Believe it or not, this is said to have happened nearly a century ago. According to lore, a small Inuit village in Canada was well known among fur trappers who visited regularly to trade. But in 1930, something very strange supposedly occurred.

A hunter named Joe Labelle claimed he visited the village one day and couldn’t find a single person. Reports said there were guns and food left behind, and even claims that the graves in the cemetery were empty. A thorough investigation, however, found no conclusive evidence of what happened to the villagers. Some witnesses from nearby towns even reported seeing a huge green light. Theories ranged from mass migration to extraterrestrial abductions. The Royal Canadian Mounted Police has since dismissed the case as an urban legend. Some still believe the story to be true.

4

The Joyita Mystery

Image: bbb

We know thousands of shipwreck stories, but this one is quite unique. The MV Joyita, designed to be nearly unsinkable, was found adrift in the South Pacific, practically unharmed, but the crew had disappeared completely.

In October 1955, the American merchant vessel left the port of Apia in Samoa with 16 crew members and 9 passengers bound for the Tokelau Islands. After days without news, a rescue mission was launched. Five weeks later, the Joyita was spotted more than 600 miles west of its intended route. The vessel was partially submerged, and there was no sign of the passengers or crew. Four tons of cargo and all three life rafts were missing. They were never seen again.

5

A mummy and a mysterious fluid

Image: Gary Todd from Xinzheng, China, CC0, via Wikimedia Commons

Do you know where one of the best-preserved mummies was found? Hint: not in Egypt. Xin Zhui, the Marquise of Dai during the Western Han Dynasty in China, was discovered in her tomb at Mawangdui 2,000 years after her death, along with hundreds of valuable documents and artifacts.

What makes this mummy so extraordinary is how well-preserved her body is. Her organs and veins remain intact, and she still has hair and even eyelashes. Scientists analyzed the fluid present in the coffin and discovered it was acidic and contained salt and magnesium. They believe this mysterious liquid may have been responsible for preserving Xin Zhui so well. What they don’t know is whether it was intentionally poured into the coffin or came from the body itself.

6

A missing prime minister

Image: Yoichi Okamoto, Public domain, via Wikimedia Commons

The United States has its fair share of presidents who died while in office, but none of our 45 presidents have ever disappeared without a trace. Did you know that this actually happened in The Land Down Under?

Harold Edward Holt was the Prime Minister of Australia from 1966 until his presumed death in 1967. He loved the ocean and spearfishing. During a weekend trip with friends, Holt visited the remote Cheviot Beach to take a swim. Rough sea conditions that day caused him to be swept away by the waves, and he never reappeared. Despite an intensive search, his body was never found, which has given rise to numerous conspiracy theories. Ironically, Australians built the Harold Holt Memorial Swimming Centre in Melbourne in his honor.

7

The anonymous hijacker

Image: FBI, Public domain, via Wikimedia Commons

Many famous criminals have managed to remain unidentified for decades, but the D.B. Cooper case is something else entirely. In 1971, Cooper boarded a flight from Portland to Seattle. Shortly after takeoff, he showed a flight attendant a device he claimed was a bomb and demanded four parachutes and $200,000 in cash.

The crew landed to meet Cooper’s demands in exchange for the passengers and then took off again. As the plane flew over southwestern Washington, Cooper jumped into the cold, rainy night carrying his haul. His whereabouts and true identity were never discovered, although it is likely he didn’t survive the jump. In 1980, some of the ransom money was found near the Columbia River. Although the FBI officially closed the case in 2016, amateur sleuths continue to try to crack it.

8

Dancing to death

Image: Pieter Brueghel the Elder, Public domain, via Wikimedia Commons

Can you imagine an epidemic where the main symptom is uncontrollable dancing? Sounds like science fiction, doesn’t it? Yet this really happened during the Middle Ages. In 1518, a dancing plague struck Strasbourg, Alsace, in what is now France. This strange condition affected up to 400 people, making them dance frantically for weeks. It is said that some even died of heart attacks, exhaustion, or strokes.

Doctors and authorities tried all kinds of measures to stop the spread. They even banned music for a while! To this day, scientists are not certain what caused this bizarre condition: it may have been food poisoning from toxins in the ergot fungus, or perhaps a case of stress-induced mass hysteria.

9

A manuscript no one understands

Image: Public domain, via Wikimedia Commons

The Voynich manuscript is a codex written roughly 500 years ago in an unknown language and writing system by an anonymous author. Known as Voynichese, the manuscript was named after Wilfrid Voynich, a Polish bibliophile and antiquarian who purchased it in 1912.

Radiocarbon testing has shown that it dates to the early 15th century. Many cryptographers and codebreakers have attempted to decipher its roughly 240 pages without success. The manuscript contains diagrams and illustrations of unknown plants and astrological symbols. Some believe it may be a made-up language, a secret code, a work of fiction, or even a hoax. If you think you can solve this mystery, the Voynich manuscript is available for viewing at Yale University’s Beinecke Rare Book and Manuscript Library.

10

An ancestor of movable-type printing

Image: Bernhard

Similar to the Voynich manuscript, the Phaistos Disc is a fired clay disc believed to have been created during the Bronze Age. It was discovered by an Italian archaeologist in the basement of a palace in Crete, Greece, in 1908.

What makes this disc fascinating is that it contains a mysterious message. Stamped into the clay is a set of signs, forming a text that many scientists have tried to decipher—without success. It is considered an early attempt at printing, a technological innovation that would not become widespread for several centuries. While enthusiasts still hope the enigma can be solved, this is unlikely unless other documents are discovered to provide context.

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