“Be in the know”in other languages

Same idea, different pictures

English and Spanish treat knowledge as a place you're inside. For Spanish it's the garlic, estar en el ajo, said of being in on a secret, often a slightly shady one.

Dutch knows where Abraham gets his mustard, weten waar Abraham de mosterd haalt: someone who knows how things really work. Why Abraham, and why mustard, nobody has explained convincingly.