(idiomatic) To be knowledgeable about, and competent at, a particular subject or task.

Alternative form of God knows (“it is unknown to people”)

(informal) I know; I am very familiar with it (some stated fact).

Alternative form of know what is what

(idiomatic) To be experienced or well-informed. / (idiomatic) To be astute, perceptive enough to observe a situation that is not what it seems and recognize its true nature.

Alternative form of know inside and out

(transitive, simile) To have an extensive and penetrating understanding of (something or someone).

Alternative form of God knows, in sense of something unknown to mortal men.

Alternative form of God knows, in sense of something unknown to mortal men.

To be spoiled; to have an easy life without appreciating it.