It is when one begins to lose the consciousness of freedom, and when the idea of necessity enters the world at all, when there is any hurry or strain anywhere, a letter to be written or a train to catch, when you have got to work, to make the horses of the dream gallop, or to make the rifles go off, that the dream is declining, and turning into the nightmare, which belongs to the poorest and most vulgar class of dreams.

Out of Africa (ed. Penguin UK, 2001) - ISBN: 9780141913872