Secret Reasons You Don’t Know About Everyday Things

From the same expiry date on all crisps to why snorkels aren’t as long as you’d like them to be, here are 10 more common secrets hidden in everyday things.

10. Sign on the Line—or Not

©Bart Everson

When signing a check, you may think you’re signing on the signature line. But if you get a magnifying glass and look very closely at that line, you’ll discover a common secret. It is actually made up of repeating print which says, “Authorized signature” over and over.


The print is so small it appears to be a regular straight line at first glance. If you look carefully you should be able to make it out. This is done as a security feature— technically called microprinting. It is where the print is so small that if photocopied, it becomes an actual blurry line. So if you want to check if your check is real, squint at the “line” where you sign.

9. Blank Pages

If you’re an avid reader of paper books, you may have noticed there are often blank pages at the end of the book.


Why are they there?  No, it’s not so you can free-form your thoughts before typing out your actual Amazon review of the novel. Books are made up of digitally printed and folded sheets of paper called signatures. They’re all bound together, attached to a cover, and that makes up your book.


Digitally printed signatures can be anywhere from 2 to 48 pages, depending on the press. Sometimes the text ends before the last page of the last signature. This is how large publishers print books, but print-on-demand services for self-published authors may be different. They print several pages on one large piece of paper, which is later cut.

©juanjo fernandez 

In this case, you may have fewer pages than would fit on the large printing sheet, and you get some blank pages.

8. Tram/Train Criss-Crossing Overhead Line

While riding the tram, you may look up and notice its criss-crossing overhead lines.

©Thomas B.

Are they designed that way to remind you of a nineties rap song? No, there’s a functional reason for the criss-cross pattern, called the ‘sweep’ exists. Trams, and some trains, run on a pantograph-catenary system, where the electricity is transferred from the catenary wire to the locomotive. The sliding strip creates the electrical contact with the catenary wire, while the pantograph spring system maintains permanent contact at any speed. The wear and tear from the sliding strip touching the copper wires can cause erosion on the pylons. The actual reason for the Criss-crossing lines is to spread the erosion and wear evenly along the contact strips. This prevents grooves from developing so that they can last longer.

7. Snorkels

You may know that snorkels allow people to breathe while swimming underwater. Unlike scuba equipment, which requires an air tank, snorkels stick up out of the water, allowing the wearer to breathe air from the atmosphere.


Most snorkels are about 30 centimeters long, and none are longer than 40 centimeters. Naturally, this limits a person to staying close to the surface. Wouldn’t a longer design be convenient?

No, actually, it wouldn’t, and this is why they aren’t that long. In deeper water, the surrounding water pressure is higher. Your lungs would be unable to inflate when the snorkeler inhales, because the muscles that expand the lungs are not strong enough to operate against the higher pressure. This problematic pressure difference across the tissues in the lungs, between the blood capillaries and air spaces would increase the risk of pulmonary edema. Using a snorkel also causes wearers to re-inhale some carbon dioxide, and a smaller tube reduces the problem. The reason scuba divers can breathe though is because they carry their own source of breathing gas, usually compressed air.


They don’t rely on breathing air under pressure from the surface. So stick with your 30-centimeter snorkel—the idea for a longer one is all wet.

6. In N Out Burgers’ Bible Verses

©Caroline Culler

Many people enjoy In N Out Burgers. Some have noticed their burger wrappers, fry containers, and cups contain tiny notations in strange places, like the underside of cups or near the seam of the burger or fry pouch. This common secret is easy to overlook, but some sharp-eyed consumers have noticed them.

©Bobak Ha’Eri

If you look closely and have studied a bible, you may realize these notations refer to bible passages—for example, John 3:16 or Proverbs 3:5. Some believe a conspiracy is afoot, that In N Out represents a sect or cult, or that they hold secret bible study classes at their location. But most people don’t even notice these notations. Moreover, the actual bible verses don’t appear on the wrappers, so as far as conspiracies go, it doesn’t hold water.


Fortunately, your cup does. In reality, the practice began in the eighties; it simply represents the Christian beliefs of the Snyder family, who started In N Out and still own most of the company.

5. Incandescent Light Bulbs

Light bulbs light up our lives, but have you ever wondered about their shape? Often hidden under a lampshade, they could be shaped like anything, but the bulb has a round shape that tapers down to the base.


This was chosen when light bulbs were first developed because it was easily made by glassblowers. The spherical design is also ideal for controlling heat and light emissions. Lately, these have been replaced by the newer, more efficient spiral-shaped bulbs.


However, sometimes, even that design is hidden inside a spherical bulb— a bright idea in design.

4. Toothpaste Stripes

This one might come as a surprise. Multicolored stripes on toothpaste were first introduced to the oral hygiene market by Aquafresh in 1973 when it entered the toothpaste market.

©Steve Buissinne

Although insanely simple, this product development was pretty ingenious. Back then, there was a growing awareness and interest in having a toothpaste that not only prevents decay, but also promotes fresh breath. In order to capitalize on this, toothpaste brands like Aquafresh divided their toothpaste up with different colors to represent the benefits of its product. It originally had two colors for double protection by combining a “white” fluoride toothpaste for cavity and decay protection and a blue “aqua” gel for fresh breath. Later, a third red gel was added for healthy gums and plaque prevention.

©Carla Manincor

As such, they now exist as a way to illustrate the product’s core benefits. You may be thinking its rather obvious, but here’s the common secret of this one… Most non-striped toothpaste offers the exact same hygienic benefits. Striped toothpaste isn’t necessarily special. In fact, the only thing that’s special is us because we think we’re getting a lot more than other standard white brands. In reality, all that’s happened is that companies have differentiated their products to match our strange preferences because research has just shown that most buyers now prefer the stripy variety over the plain old white product.

3. McFlurry Spoon Hollow Bottom

If you enjoy McDonald’s McFlurries, you may have thought the hole at the end of the McFlurry spoon was meant to be used as a straw.


Makes sense, right? As the McFlurry melts, you could easily enjoy it as a milkshake. But that’s not the reason for the hole in the spoon. When the McDonald’s worker makes your McFlurry, they put ice cream in the cup, add the candy or cookies, then place it in a machine that automatically stirs it…with the spoon that comes with it.


The hole on the end allows the spoon to attach to the machine, so your McFlurry can go through an appropriate blizzard of stirring before you consume it.

2. Walkers Crisps

Most consumers are so eager to tear the bag of Walkers Crisps open they don’t pay much attention to the date. But some discerning people have noticed a common secret that the bags always go out of date on a Saturday—a little inconvenient if you consistently pig out on walkers chips only on Sundays.


So, does the flavor take a holiday on Saturday night or what?  It turns out the reason is because of Walkers’ production schedule, which starts on a Sunday. That means all bags will have an expiration date on Saturday. However, many of us know chips usually taste okay for a few days after that date, so don’t be too worried about that date.

1. Who Killed the King of Hearts?

If you’ve ever been bored during a card game, you might have pondered at the design of the cards. Some people have noticed the King of Hearts actually has a sword stuck in his head, or at least that’s how it appears on the card.

©Gina Janosch

If you look at the top of the card you might think he’s stabbing himself in the head. That may be consistent with the fact that the card is thought to be based on France’s King Charlemagne, who was rumored to have gone insane and put a sword through his head, hence the term “suicide king”. However, looking further down we can see both his hands are accounted for, so the hand holding the sword belongs to someone else.  Is this a case of Lover’s quarrel with the Queen of Hearts, maybe? Actually, some people believe it’s the Queen of Spades.

©Poker Photos

However, if you look carefully at her sleeve, the pattern is similar, but not exactly the same. The Jack of Hearts is another suspect—although his sleeves aren’t shown… but his clothes have a similar pattern.

©Gina Janosch

In truth, the sword actually appears to be going into the King’s head due to poor card copying over the years. The earliest forms of the card featured an axe head, which disappeared after several generations of inexact copying.

via Wikipedia

If you were interested in that fact about the king of hearts then you should watch this video, it has another hidden secret on the card you might not have noticed. Also, are there any other common secrets about everyday things that you know of? Let us know in the comments below!

You can watch this article in video form below: