What is the origin of the idiom "like a dream" and when to use it?

The idiom "like a dream" draws its origin from the concept of dreams and the ethereal, imaginary experiences they entail. The phrase is used to describe something that is exceptionally pleasant, perfect, or ideal, resembling the characteristics of a dream. It suggests a state of bliss or enchantment, often used to emphasize the extraordinary or magical nature of the subject.