What's the stupidest thing anybody ever said to you?

We already know there's a lot of science misinformation out there, from bad mental health advice to widely-held – but completely false – beliefs about cancer.

And, when they're not busy being mistaken for serial killers, scientists often try to combat these myths on social media – but, as a recent viral tweet is proving, there's still a lot of people out there who haven't got the message.

Recently, Twitter user Mark Magark asked people for their submissions for the most confused, ignorant, and just plain wrong things they'd been told. Specifically, he asked for something "so astonishingly stupid" that it had stayed with them ever since.

And it turns out that, despite our best efforts, people are just as confused as ever. About... well, everything.

Unsurprisingly, it seems a lot of people are suffering from some severe medical misconceptions.

 And one thing's for sure: the female body, in particular, is still as big a mystery as ever for some people out there.

Obviously, no, women can't "just hold it in" when it comes to menstruation – if they could, astronauts wouldn't need space gynecologists, and period poverty wouldn't be a thing. Though, while we're on the topic of things that will stop your period:

In fact, it's fair to say that people are confused about human biology generally.

And humans aren't the only species people are puzzled by.

We can confirm that Donkey from Shrek is, in fact, a donkey – as is the character of the same name in the celebrated sequel to Shrek, Shrek 2.

Geography is not a strong area for a lot of people:

Although neither is physics...

... or, um... history of art?

And we can only sympathize with the guy who had to deal with this museum visitor.

Some comments started to stray into the metaphysical – or the completely nonsensical.

And it turns out some people are really overthinking the fate of the human race – or, perhaps, underthinking it.

But one thing's for sure – when it comes to being really, really dumb, doctors in particular know that humanity will never change.