If you believe hard enough anything is possible.
This statement is not to be believed nor is it backed up with any hard data.
Sometimes something that is presented as fact is done so for sinister reasons or to propel a particular ideal. It's pretty common when nations have wanted to go to war to spin certain events so that the truth can look more favourable to their cause.
Other times, humans have just been known to get something wrong. There's nothing inherently bad about this, so long as you are willing to accept your theory or understanding may one day prove to be incorrect.
We shouldn't hide from our mistakes. We should embrace them, especially when they were not perpetrated through evil, but through ignorance.
With all that understanding it's still pretty hilarious to go back in history and gaze at our idiocy. It's like looking at humanity's own fail compilation.
Many of the following have at least a smidgen of truth in their origins. Nothing presented is a flat-out lie; more an exaggeration or misinterpretation. But looking back we can really see, much like reading our schoolworks from years gone by, that we used to be kind of stupid.
10. Babies Don't Feel Pain
Babies are hard, well hard. They can walk (crawl?) through all manner of chaos and calamity, through bullets and explosions, and shrug it off because they feel no pain.
Except that they do. Babies can feel pain; please for the love of God don't believe they can't.
The oddest thing about this belief is that we did initially believe (know, surely?) that babies had the capability to feel pain. Sometime in the 19th century this belief got turned on its head.
Infants were considered underdeveloped in terms of being able to distinguish pain or even understand it. This led to many simple surgeries being conducted on babies with only muscle relaxants and no anaesthesia.
The idea stemmed from pinprick studies conducted in the 1940s, where infants didn't react to being poked in the arms and legs. It was thought that it was because they felt no pain, but was actually because their limbs were underdeveloped (and, you know, new) so they didn't always have reactive capabilities.
Anaesthesia can be a rather difficult thing to administer to such a small body so in certain cases this makes a little sense. But there seems to have been a collective blindness within the whole 'babies can't feel pain' theory, which was only really disproven in the '80s. The 1980s.