TRUE!–nervous–very, very dreadfully nervous I had been and am; but why will you say that I am mad? The disease had sharpened my senses–not destroyed–not dulled them. Above all was the sense of hearing acute. I heard all things in the heaven and in the earth. I heard many things in hell. How, then, am I mad? Hearken! and observe how healthily–how calmly I can tell you the whole story.
Edgar Allan Poe, “The Tell-Tale Heart”