5. Vikings

What would a Viking be without his trusty battle helmet and its impressive horns? The answer is: a more historically accurate Viking. Think, for a moment about wearing headgear like that into battle: the horns are just easy targets for your opponent to hit and knock off your helmet. Or, if you strap on your helmet, now your opponent has a convenient lever with which to drag you to the ground and something to hold onto while slitting your throat. Horned helmets are a terrible idea, which is why archeologists have never found them at Viking battle sites and there's no evidence that they were ever used. It was poets and artists -- people not known for caring about facts and reality -- who gave the Vikings their silly hats during the late 1800s, long after the Vikings could 'correct' their misconceptions.

4. Lady Godiva

The story of this 11th-century English noblewoman is that her mean husband, the Earl, raised taxes on the townspeople of Coventry, which Lady Godiva -- and not surprisingly the locals -- thought were too high. She badgered her husband and he conceded in exasperation to lower the taxes if she rode through town naked -- assuming that she never would, but she did. Because people don't like taxes -- even though they're how civilization is purchased -- Lady Godiva's story lives on notably in the Godiva logo and in popular songs. But while Lady Godiva was a real person and Coventry is a real town, there is no record of her nude ride from the time when it happened -- so we can assume the story is false. Just as with the Vikings, again poets and artists are to blame, who made up the tale long after Lady Godiva's death.

3. Napoleon

Famously, this tiny, tiny general -- perhaps to compensate for his short stature -- took control of France, greatly expanded its influence, and dubbed himself emperor. Napoleon's official height was indeed 5 foot 2 inches, but at the time French inches were longer than English inches, so doing the unit conversion, Napoleon's height should have been reported as 5'7 in England's imperial units -- which is short by today's standard but was average or slightly above average in the early 1800s. However, England, with its eternal love for all things French, didn't care and went the Napoleon-is-so-short-LOL version of the story in newspapers and cartoons. Meanwhile, Napoleon was busy introducing the Metric System to France and the wider world to standardize measurements so this sort of confusion would never happen again -- and thankfully the whole world now uses metric. Mostly. Sort of.

2. Roman Vomit

Ah, the Roman Empire, so great and powerful, but corrupted by decadence from within. And what could be a better symbol of that decadence than the Vometorum: where Romans, after stuffing themselves with delicious foods, could vomit them all up to make room to feast anew. Vometoria are real, but this idea of them is not, though confusion is understandable because their name -- Vomit-orium -- seems to make their purpose so clear. Even if for some reason you know Latin -- perhaps because you live in a country that insists you waste hundreds of hours of your life learning a dead, useless language -- this knowledge still won't help you because the root word 'vomitum' means 'to spew forth'. So what is it really? If you've ever been to a big stadium, like say, the ones made by the Romans, you have already used a vometorium. This is what the vometoria are -- the passageways that let lots of people enter or exit at once. The people are what spews forth in the vometoria, not the contents of the people.

1. Columbus

There is so very much wrong with the common retelling of the story of Christopher Columbus that it's hard to know where to begin, but the biggest misconception is that everyone else thought the world was flat, but Columbus was the only guy smart enough to know that it's round. It makes a daring story, but knowledge of a spherical earth goes back to at least 5,000 BC -- that's six and a half thousand years before Columbus set sail -- and that knowledge was never lost to Western civilization. In 200 BC, Eratosthenes calculated Earth's circumference and his estimate was still well known and being used in Columbus's time. The argument Columbus had with Queen Isabella was not over the shape of the earth, but of its size. Columbus estimated the Earth was much smaller than Queen Isabella and her scientific advisors did, which was why he thought he could make it across the empty Atlantic to India. But Columbus's size estimate was wrong -- again, just like Napoleon's height -- because of mixed-up units. However, his error did send him West to become the first European to discover America -- as long as you ignore the hornless Vikings who beat him by 500 years.