1. Cracking Your Knuckles Causes Arthritis
For years, people have warned that cracking your knuckles would leave you with swollen, arthritic fingers. The sound can be annoying, sure, but research hasn’t found any link between knuckle cracking and arthritis. What actually causes that “pop” is just gas bubbles bursting in the joint fluid. It might sound dramatic, but it’s harmless for most people.
At worst, chronic cracking could make your hands a little swollen or weaker in grip strength, but even that’s debated. One doctor even cracked his knuckles on one hand for decades and never developed arthritis in that hand compared to the other. So while the habit might drive people around you crazy, it won’t guarantee a future of stiff, aching joints.
2. Going Outside with Wet Hair Makes You Sick
How many parents warned their kids about this one? The idea is that cold air plus damp hair equals an instant cold. But the truth is, viruses cause colds, not weather or wetness. You could stand outside with dripping hair in the middle of winter and still stay healthy—so long as no germs find their way to you.
That said, being cold can stress your body a little and make you more vulnerable to catching something if you’re exposed. So while it might not directly cause a cold, it could play a small role in lowering defenses. Still, the real culprit isn’t the chill, it’s other people coughing and sneezing nearby.
3. You Only Use 10% of Your Brain
This myth has been repeated in movies, books, and casual conversation for ages. The idea that unlocking the “unused” 90% could give us superhuman powers sounds exciting, but neuroscience says otherwise. Brain scans show activity all across the brain, even when we’re resting.
Sure, we may not use every part at once, but over the course of a day, nearly all areas serve some purpose. The myth stuck around because it makes us wonder about hidden potential, but the reality is, your brain is already firing on all cylinders. No unused superpower switch is waiting to be flipped.
4. Gum Stays in Your Stomach for Seven Years
Chew gum, swallow it by accident, and suddenly you’re told it will sit inside you for nearly a decade. Thankfully, your digestive system is much more efficient than that. Gum base is indigestible, so your body doesn’t break it down, but it doesn’t get stored either.
Instead, it passes through your system like roughage, right along with other fiber you eat. It might not dissolve, but it also doesn’t cling to your stomach walls for years. Parents probably started this myth to discourage kids from swallowing gum, but the truth is much less dramatic.
5. Carrots Improve Your Night Vision
Carrots are healthy, no doubt, but they won’t turn you into a superhero who can see in the dark. This myth really took off during World War II when British propaganda spread the idea to explain why their pilots were so successful at night. In reality, it was radar technology doing the work, not carrot-loaded diets.
Carrots do contain vitamin A, which supports eye health and can prevent night blindness from deficiency. But once you’ve had enough vitamin A, eating more carrots doesn’t give you sharper vision. So yes, carrots are good for you—but don’t expect them to replace night-vision goggles.
6. Sitting Too Close to the TV Ruins Your Eyes
Generations of kids were told to back away from the television or risk going blind. While sitting very close might give you eye strain or a headache, it doesn’t cause permanent damage. In fact, children often sit closer simply because their eyes can focus better at short distances than adults.
Back in the 1960s, some TVs did emit higher levels of radiation, which fueled fears. But that problem was fixed long ago with better safety standards. Today, sitting close is mostly just a bad habit for comfort, not a true medical risk.
7. Sugar Makes Kids Hyper
Every parent has blamed sugar for their child bouncing off the walls, but science hasn’t found strong proof for this connection. Multiple studies have shown that sugar doesn’t cause hyperactivity in children. What usually happens is that kids are already excited at parties or holidays when sweets are involved, so sugar gets the blame.
The placebo effect also plays a role. If parents expect sugar to hype kids up, they often interpret normal behavior as over-the-top energy. That doesn’t mean sugar is harmless—it still affects health in other ways—but it’s not the instant fuel for chaos people long believed.
8. Crossing Your Eyes Can Make Them Stay That Way
It’s a warning nearly every child has heard: keep making that face, and it’ll get stuck. But crossing your eyes temporarily won’t damage them or lock them in place. The muscles around your eyes are meant to move in all directions, and they go back to normal once you relax.
In rare cases, if someone already has a condition like strabismus, crossing eyes can highlight or worsen it. But for most people, the worst that happens is a short-term ache or strain. The idea of permanently crossed eyes from a silly face is more myth than medical truth.
9. You Need to Drink Eight Glasses of Water a Day
Hydration is important, but the “8 glasses a day” rule isn’t based on solid science. The truth is, fluid needs vary depending on your body, diet, and activity level. Many foods—like fruits and vegetables—also contribute to your water intake, so you’re often more hydrated than you think.
A good measure is simply thirst. Your body is good at signaling when it needs more water, and urine color is another handy clue. Instead of rigidly tracking glasses, most people can rely on their body’s natural cues to stay hydrated.
10. Shaving Makes Hair Grow Back Thicker
This is one of the most persistent grooming myths. After shaving, stubble feels coarser, and the blunt tips of new growth can look darker or thicker. But the actual thickness and growth rate of hair come from genetics and hormones, not razors.
Shaving only cuts hair at the surface—it doesn’t touch the follicle beneath the skin where growth is determined. Once the hair grows longer again, it softens and looks the same as before. The illusion of thickness is just that, an illusion.
11. Reading in Dim Light Ruins Your Eyes
Parents have been scolding kids for reading under the covers with a flashlight for generations. While dim light can make reading harder and cause temporary eye strain, it doesn’t cause permanent damage. Your eyes might feel tired, dry, or sore, but they’ll recover once you rest them.
This myth probably persisted because of how uncomfortable poor lighting feels on the eyes. But modern research shows your eyesight won’t be permanently harmed by that late-night book binge. The worst consequence is falling asleep with your glasses on.
12. Craving Pickles and Ice Cream Means You’re Pregnant
The cliché of odd food cravings has been linked to pregnancy for decades. While some pregnant women do report cravings, it’s not a universal experience, nor is it a reliable sign of pregnancy. Hormonal changes, nutritional needs, and even cultural expectations may play roles in why cravings happen.
But pickles and ice cream specifically? That’s more pop culture than biology. Cravings can be for anything—sweet, salty, spicy, or even non-food items in rare cases. So while it makes for a funny stereotype, there’s no medical proof that wanting strange combos automatically signals a baby on the way.