You perceive, now, that these things are all impossible except in a dream. You perceive that they are pure and puerile insanities, the silly creations of an imagination that is not conscious of its freaks - in a word, that they are a dream, and you the maker of it. The dream-marks are all present; you should have recognized them earlier.

Stormfield Edition of the Writings of Mark Twain [pseud.].: The mysterious stranger (ed. 1929)