What is the origin of the idiom "away with the fairies" and when to use it?

The origin of the idiom "away with the fairies" is somewhat unclear, but it likely draws on folklore and mythology. Fairies have long been associated with enchantment, fantasy, and otherworldly experiences. The phrase is believed to have emerged in the late 19th or early 20th century and gained popularity in the British Isles. This expression is used to describe someone who is not paying attention, lost in daydreams, or seems disconnected from reality. It implies that the person is preoccupied with their own thoughts or fantasies to the point of being unaware of their surroundings or responsibilities.