Whenever nobles tell stoopid peasants how to do basics in order to justify (to the audience) why they're in charge because they're so smart:

• In Bridgerton, Duke Hastings returns to his manor to find it in disarray. He tells his peasants they have to let land lay in fallow so the ground can restore nutrients. The concept of fallow land was thousands of years old at this point, and even the 3 field system was 800 years old in Europe.

• In Kingdom of Heaven, John of Ibelin (a French blacksmith) explains to native Palestinians how to irrigate their farmlands. Europeans learned irrigation from Arabs, not the other way around.

• In a later season of Game of Thrones, Lady Sansa commands her soldiers to wear furs between their skin and armor so the metal doesn't sap their heat in winter. She tells this to soldiers from the land where winter lasts years.