We often think of ourselves as more capable than we really are. For example, according to this survey, four in five Americans consider themselves knowledgeable about the human body, but only one in ten knows that O-negative is the universal blood type, and only three in ten could tell the difference between a liver and a kidney. So, to stay grounded and remind each other that there’s always something new to learn, people on the internet have been sharing their favorite obscure medical facts. Here are some of the most fascinating ones!

#1

* The same process that turns food brown when cooked (caramelization, or the 'Maillard reaction'), also occurs in our blood vessels as body heat causes sugars to bind to cell proteins. We just call it "glycation" instead.
* Shellfish allergies are also triggered by snails and other land-based molluscs. No escargot for you.
* If you are born blind due to lesions in the brain (congenital cortical blindness, rather than lesions in the eye (congenital peripheral blindness)), you apparently can't become schizophrenic. Zero known cases.
* Microgravity causes bacteria to rapidly become resistant to virtually every known antibiotic currently available (edit: upon exposure, I should clarify). Interplanetary and interstellar travel will resemble the Oregon Trail a lot more than we'd hoped.
* The idea that amputee patients can still feel their lost limb (phantom limb syndrome) is fairly well known even in the public. What I've not seen mentioned so much is that somewhere around half of amputees with the syndrome report being able to move their 'phantom limb' projections in impossible ways, complete with phantom sensation. Rotating a wrist 360 degrees or bending an elbow backwards.
* There are twins born over a month apart (90 days is the record). Usually when the mother goes into labor prematurely and the doctors were able to stop it, but only after the first child is born.
* Some deaf people with tourettes syndrome involuntarily sign curse words with their hands.