"In a morbid condition, dreams are often distinguished by their remarkably graphic, vivid, and extremely lifelike quality. The resulting picture is sometimes monstrous, but the setting and the whole process of the presentation sometimes happen to be so probable, and with details so subtle, unexpected, yet artistically consistent with the whole fullness of the picture, that even the dreamer himself would be unable to invent them in reality, though he were as much an artist as Pushkin or Turgenev. Such dreams, morbid dreams, are always long remembered and produce a strong impression on the disturbed and already excited organism of the person."
Fyodor Dostoevsky
Crime and Punishment