9 Common Myths, Fact-Checked

Tap a myth to see what's actually true.

Myth: Humans only use 10% of their brain

False. Brain imaging studies show people use nearly every region of the brain over the course of a day for various activities — no region sits completely idle.

Myth: Goldfish only have a 3-second memory

False. Research shows goldfish can remember specific patterns or cues for months at a time.

Myth: Napoleon was extremely short

Not accurate. Napoleon's actual height was about 5'6"-5'7" (168-170 cm), close to the average French male height of his time. The "short" image is thought to stem from confusion between British and French measurement units, plus political satire.

Myth: The Great Wall of China is visible from space with the naked eye

False. Astronaut testimony and photos confirm the wall is too narrow to be distinguished by the naked eye from space.

Myth: Bulls get angry when they see red

False. Bulls are effectively color-blind to red and green — what provokes them during bullfighting is the movement of the cape, not its color.

Myth: Sugar makes children hyperactive

Multiple double-blind studies have found no direct causal link between sugar intake and hyperactivity in children.

Myth: Cracking your knuckles causes arthritis

Multiple studies have found no significant correlation between knuckle-cracking habits and the development of arthritis.

Myth: Food dropped on the floor is safe if picked up within 5 seconds

False. Bacteria can transfer to food on contact instantly — the "5-second rule" has no scientific basis.

Myth: Sharks don't get cancer

False. Tumors and cancer cases have been documented in sharks — this myth spread largely through marketing for unverified health supplements.

Why do false myths like these spread?

Many myths originate from flawed past experiments, sensationalized media coverage, or stories that grow more exaggerated as they pass from person to person. Once a myth takes hold, it often gets repeated without fact-checking until it hardens into something that feels like established truth.

Frequently Asked Questions

Is everything on this page confirmed scientific fact?

The content here is compiled from multiple scientific studies and credible sources, but science keeps evolving — new research may update some of these conclusions over time.

Are there more myths like these out there?

Yes, there are far more widely believed myths beyond what's covered here. It's a good habit to verify anything you're curious about through credible sources.