Someone knocks at the door of an apartment to borrow salt or sugar, people run into each other in the elevator, and in this way become inscribed in the spectator's memory.
A lot of knowledge in any kind of an organization is what we call task knowledge. These are things that people who have been there a long time understand are important, but they may not know how to talk about them. It's often called the culture of the organization.
The British have a remarkable talent for keeping calm, even when there is no crisis.

