10 Everyday Items Hiding Weird (and Cool) Facts You Probably Never Knew

We use them every day without a second thought. Toothbrushes, pencils, mirrors, coffee mugs…they’re just there, doing their thing. But honestly? Some of the most boring stuff in your house has pretty wild backstories and facts hidden under the surface.

I fell down the research rabbit hole (as one does when stuck at the airport) and found 10 fun, weird, and honestly mind-blowing facts about everyday objects you probably never thought twice about.

Ready to see your stuff a little differently?

1. Your Toothbrush Is Dirtier Than Your Toilet (Sorry)

Hate to break it to you, but studies show your toothbrush can harbor 10 million bacteria…including E. coli and staph. Yep. And if it’s sitting out near your toilet? Every flush sends a mist of germs into the air that can land right on those bristles.

Gross? Absolutely. But good news: rinsing it under hot water and letting it dry upright in open air reduces bacterial growth. You don’t need to toss it after every cold (unless it’s super nasty), but replacing it every 3-4 months is key.

Want to level up? I swear by using a UV toothbrush sanitizer. I started using one after reading this stat, and now I can’t go back.

2. The Average Pencil Can Draw a Line 35 Miles Long

I always thought pencils ran out way too fast, but turns out, a single No. 2 pencil holds enough graphite to draw a line about 35 miles long. That’s like drawing a straight line from Philadelphia to Trenton… with one pencil.

It can also write around 45,000 words…enough for a short novel. Not bad for something most of us break or lose within a week!

(Also: fun bonus fact, the eraser is only about 1/5th as long-lasting as the graphite. So don’t make too many mistakes!)

3. The Tiny Hole in Pen Caps? It Saves Lives

Ever notice that little hole in the top of a ballpoint pen cap? It’s not there to stop ink drying out or balance air pressure (common myths). It’s literally a safety feature to prevent choking.

If someone accidentally swallows the cap, the hole keeps air flowing through so they can breathe while getting medical help.

In other words, that tiny hole? It’s a literal life-saver.

4. Mirrors Flip Front to Back…Not Left to Right

We’re all taught mirrors reverse left and right… but technically, they don’t. A mirror reverses front and back.

It feels like left/right because we instinctively think about turning around to face ourselves, but optically? The mirror keeps left and right the same…it’s the depth (into the mirror) that flips.

Basically, mirrors are messing with your brain more than your eyes.

Speaking of reflections, if you’re into light, mirrors, and cool science intersections, check out my article about the science of static electricity. Weird physics party, anyone?

5. The Mug Handle Was Invented for Hot Beer (Not Coffee)

Coffee wasn’t the OG beverage needing a mug. Handles were originally added to ceramic drinking vessels in medieval Europe so people could hold hot beer without burning their hands.

Yup, beer.

Before coffee even arrived in Europe, beer was served warm or at room temp, and sometimes boiled as part of the brewing process.

So next time you’re holding a steaming cup of joe by the handle, thank beer drinkers from the 1400s.

6. Keys Used To Be Worn Like Jewelry

In ancient Rome, keys weren’t hidden in purses or pockets…they were worn as rings. If you were wealthy enough to own property or valuables, your key literally doubled as a status symbol on your finger.

It was partly practical (keys were hard to keep track of otherwise) and partly a way to flex that you had something worth locking up.

Can you imagine your house key as part of your outfit?

7. Microwaves Were Invented By Accident

The microwave wasn’t invented in a lab testing food…it was discovered when an engineer working on radar tech during WWII noticed a chocolate bar melted in his pocket while standing near a magnetron.

Percy Spencer realized the radiation was cooking the chocolate… and a few experiments later, the microwave was born.

Fun fact: the first microwaves were the size of a refrigerator and cost about $5,000.

8. Salt Was Once So Valuable It Was Used as Currency

The word “salary” literally comes from “salarium”, the payments made to Roman soldiers for buying salt. Salt was so critical for preserving food, disinfecting wounds, and tanning hides that it was a key part of trade and economy.

Owning salt = having power. Wars were fought over salt mines. Entire trade routes were built around moving it.

Kind of wild that today we just casually toss it in pasta water.

9. Corkscrews Were Modeled After Gun Tools

The first corkscrews were actually based on a “gun worm”, which is a tool used to pull stuck bullets and wadding out of musket barrels. Winemakers and tavern owners in the 1600s realized a similar spiral tool could be used to pull corks out of wine bottles.

So next time you open a bottle of wine, you’re literally using tech borrowed from old-school warfare.

(Also explains why some corkscrews look so medieval.)

10. The Color of Your Walls Can Literally Change Your Appetite

Ever wonder why so many fast food restaurants use red and yellow in their branding? Or why hospitals use pale greens and blues?

Colors actually trigger psychological responses:
Red and yellow = stimulate hunger and urgency
Blue = calming and appetite-suppressing
Green = associated with health and relaxation

Interior designers and branding experts deliberately choose color palettes to influence behavior…and it totally works.

So if you’re trying to eat less? Maybe skip painting the dining room red.

Everyday Stuff, Way More Interesting Than You’d Think

It’s kind of wild how many ordinary objects have weird, forgotten, or downright fun histories behind them.

I guarantee the next time you sip from a coffee mug, flip a light switch, or write with a pencil, you’ll think twice about how those things came to be.

Do you know any weird facts about everyday things? Send me an email! I love learning this kind of trivia!