An ability to absorb, understand and conform successfully to the rules and norms of mainstream society or one of its subcultures.
Raymond: We have pepperoni pizza for dinner Monday nights.
Susanna: Pizza? You get pizza in an institution?
Raymond: Monday night is Italian night. It's normal knowledge that pepperoni pizza is associated with Italian culture.
A mysterious body of knowledge, usually related to the relationships between men and women, that some say is denied them.
First discovered on a relationship forum in late 2010 / early 2011; a young man insisted that forum members were blocking him from acquiring "normal knowledge" of relationships. When queried about the nature of this knowledge, said young man refused to answer, resorting to an annoying repetition of "Why are you denying me normal knowledge?!?"
I want to know why you say I should just go out on a date, instead of sitting here on the forum asking questions?!? What do you mean? Why are you denying me normal knowledge?