Things that I am SHOCKED shocked that other people don't know: There is no such thing as one monolithic body of knowledge known as common sense. As I have mentioned before, I have been reading The Spirit Catches You and Then You Fall Down. In the Hmong society, it is common sense that you bury the placenta so that the baby's soul will have something to wear when it (eventually) dies. However, in the US, this would be a strange, non common sensical belief.

Even within cultures, common sense varies sometimes from person to person. I may consider it common sense that what your brother's friend's sister's step grandma's cousin's roommate said is not the most accurate source of information on anything, but Bob down the street may think it's common sense that what regular people say is better than what some liberal radicals say in those fancy books. Doctors and lawyers have a different sense of common sense than farm laborers, because the knowledge base and the experiences are different.

We are not all starting from the exact same base of knowledge, and it'd be crazy to think we do.