When you dig into these 10 obscure things, you’ll quickly see that many of them are hiding in plain sight. It’s all too easy to stay inside a personal bubble—watching only one news channel, eating the same cuisine, or sticking to a single movie genre—while missing out on the myriad ways the world is more interconnected than we imagine. That tunnel‑vision can make us believe something is rare or niche, when in fact it’s wildly prevalent. Let’s bust those myths together.
Why 10 Obscure Things Matter
Understanding the hidden ubiquity of these topics not only broadens our perspective but also sharpens our appreciation for the subtle threads that stitch together everyday life, science, history, and even tragedy. From the ocean’s midnight glow to the quiet hum of a phone on hold, each entry reveals a surprising layer of commonality that most of us never consider.
1 Lysol Was Once the Most Common Form of Suicide in Australia
Suicide remains a grave public‑health issue, and anyone wrestling with depression or overwhelming thoughts should seek trusted support immediately. In the United States today, firearms account for roughly 52 % of self‑inflicted deaths, making them the most frequent method.
Back in 1911, however, Australians faced a very different reality. The household disinfectant Lysol, cheap, readily available, and brutally toxic, emerged as the leading means for people to end their lives. Its accessibility turned it into a tragic, yet common, choice for those desperate enough to act.
Historical newspaper reports from that era document the startling prevalence of Lysol‑related fatalities, underscoring how a seemingly innocuous product can become a public‑health hazard when circumstances align. The episode serves as a sobering reminder that the most common tools can sometimes be turned toward the most devastating ends.
2 Opus Number One Is the Most Common Hold Music
If you’ve ever been stuck on a telephone line listening to a soft, synth‑laden melody with a gentle beat, you’ve probably heard the world’s most ubiquitous hold music. This tune, known as Opus No. 1, has become the default waiting soundtrack for millions of corporate phone systems worldwide.
Composed in 1989 by a 16‑year‑old teenager named Tim Carleton while tinkering in his parents’ garage, the piece was later discovered by a Cisco employee who loved the track. After securing Carleton’s permission, Cisco rolled the composition out across its entire phone network, and today more than 65 million Cisco devices play it whenever callers are placed on hold.
3 Plasma Is the Most Common Form of Matter
Most of us learned in school that matter exists in three states—solid, liquid, and gas—before a fourth, plasma, was added to the curriculum. While the first three are familiar, plasma is a far more abundant state of matter than many realize.
Scientists estimate that roughly 99 % of the observable universe’s mass is in the plasma state. It behaves like a super‑heated gas in which electrons have been stripped from atoms, creating an ionized soup that powers stars, nebulae, and the dazzling auroras we see in the night sky.
Even though we rarely encounter plasma on Earth’s surface, its dominance in the cosmos makes it the most common form of matter overall. From the Sun’s fiery core to distant quasars, plasma is the invisible engine behind the universe’s most spectacular phenomena.
4 An Herb Called Laser Was One of the Most Valuable and Common in Ancient Rome
Long before the word “laser” became associated with high‑tech light beams, ancient Romans prized a plant known as silphium—sometimes referred to simply as laser. This herb thrived in the region that is now modern‑day Libya and quickly became a cornerstone of the Mediterranean economy.
Silphium’s versatility was legendary: it served as a medicine, a culinary seasoning, a perfume ingredient, and even a contraceptive. Its high demand turned the harvesting city into one of the wealthiest locales of its time, with Roman leader Julius Caesar reportedly storing 1,500 pounds of its resin in the state treasury, valuing it at its weight in silver.
Unfortunately, the plant’s popularity outpaced sustainable harvesting practices, leading to its eventual extinction. Today, silphium lives on only in historical records and the occasional coin bearing its stylized image.
5 Faro Was the Most Common Kind of Gambling in the Old West
When you picture the Wild West, poker tables and saloon dice games typically spring to mind. Yet, during the 19th‑century frontier boom, a different card game reigned supreme: faro.
Originating from the French court of Louis XIV, faro spread to America and became the headline attraction in virtually every gambling hall, from Washington D.C.’s bustling establishments to the dusty towns of the frontier. By the Civil War era, over 150 gambling houses in the capital featured faro as their marquee offering.
The game’s mechanics are straightforward yet thrilling. A banker deals one card face‑up (the “banker” card) and another to the players as a group (the “player” card). Participants wager on which side will win; betting on the banker’s card loses, while backing the player’s card wins. Its rapid pace and simple betting structure made faro a favorite among gamblers of all stripes.
6 The Most Common Form of Entertainment for School Shooters Is Written
School shootings have horrifically scarred the United States for decades, prompting endless debates about media influence. While video games, movies, and music often bear the brunt of public criticism, data tells a different story.
According to FBI analyses, only about 27 % of shooters displayed an interest in violent movies—a surprisingly low figure. In contrast, a striking 37 % of perpetrators engaged in violent expression through their own writing, whether poetry, essays, or personal journals.
These findings suggest that the act of crafting violent narratives on paper may be a more reliable warning sign than the consumption of aggressive video games or films. Recognizing these literary red flags could prove vital in early intervention efforts.
7 The $100 Bill Is the Most Common Form of US Currency
Although many retailers refuse to accept the $100 note, fearing counterfeit risks, it actually dominates the United States’ cash circulation. In 2017, the Federal Reserve reported that the $100 bill eclipsed the $1 note to become the most widely distributed denomination.
Most Americans rarely encounter $100 bills in everyday transactions, yet statistics show they are the most common bill held by cash‑using consumers. Their popularity isn’t limited to the U.S.; a substantial portion of these high‑value notes circulates abroad, often facilitating black‑market deals and other informal economies due to their compact size, high value, and ease of concealment.
The combination of portability, liquidity, and the perception of security has cemented the $100 bill’s status as the go‑to piece of paper money for both legitimate and illicit purposes worldwide.
8 Walking Is the Most Common Leisure Activity
Many envision walking as the domain of retirees strolling through malls, but in reality it tops the list of physical activities for adults across the United States. The CDC’s research shows that walking outranks every other exercise when it comes to sheer participation.
Transportation‑related walking accounts for about 29 % of all steps taken, while a robust 50 % of Americans reported walking purely for pleasure in 2010. By 2015, the CDC noted that 65 % of women and 62 % of men listed walking as a regular leisure pursuit.
Because walking is as natural as breathing, even those who never hit the gym still log miles each day, whether heading to work, chasing a dog, or simply enjoying a park stroll. Its ubiquity makes it the most common, and arguably the healthiest, pastime available to everyone.
9 Sweethearting Is One of the Most Common Kinds of Retail Theft
Retail loss figures are staggering—$112 billion vanished from stores in 2022 alone. While shoplifting grabs headlines, another stealthy practice, sweethearting, contributes almost equally to the financial drain.
The National Retail Federation found that employee theft accounts for roughly 33.2 % of total retail losses, and a sizable slice of that stems from sweethearting. In this scheme, an employee gives a friend or family member a discount—or even a free item—without authorization, effectively stealing the merchandise.
Surveys reveal that 67 % of retail workers admitted to participating in sweethearting within two months of the study, translating to an estimated $80 million in losses. The practice highlights how internal fraud can be just as damaging as external theft.
10 Bioluminescence May Be the Most Common Kind of Communication on Earth
Human beings often assume that spoken or written language reigns supreme as the planet’s dominant communication method. Yet, deep beneath the sun‑less abyss of the ocean, countless organisms have evolved a far more luminous way to converse.
Research indicates that an impressive 76 % of creatures inhabiting the water column and 45 % of those living on the ocean floor possess bioluminescent abilities, using light flashes to convey meaning, locate prey, or signal danger.
These light displays serve multiple purposes: predators can lure unsuspecting fish, while prey species may emit invisible wavelengths that their hunters cannot detect, effectively hunting in the dark. Some species even tailor their glow to wavelengths invisible to their targets, ensuring a stealthy strike.
Beyond hunting, bioluminescence plays a critical role in mating rituals, predator deterrence, and territorial claims. Though the exact numbers are murky—owing to the ocean’s vastness—scientists argue that this glowing language could very well be the most widespread communication system on Earth.
So the next time you think of “talking” as a human‑only activity, remember the countless sea creatures flashing signals in the dark, silently chatting in a language of light that outnumbers our own conversations by far.