Bonus points if it’s usually misused/misunderstood by the people who say it
“We only use ten percent of our brains.”
People genuinely believe this and never learned where it came from.
It came from early on in studying the brain. A scientist said that we only understand what 10 percent of the brain does, and everyone ran with a misunderstanding of that idea.
Neil DeGrasse Tyson explains here. https://youtube.com/shorts/E4EjYfUBEvw?si=LO3GIURgZesHjo85
That and the “Alpha Male” garbage. Even the author of the study on wolves has said repeatedly that his study was totally wrong. And yet some people continue to reference it and apply it to humans when even the original study wasn’t about people.