[I]t appears evidently from experience that a man is of all sorts of luggage the most difficult to be transported.

Adam Smith, An Inquiry into the Nature and Causes of the Wealth of Nations, in William B. Todd (ed.) The Glasgow Edition of the Works and Correspondence of Adam Smith, Vol. 2: An Inquiry into the Nature and Causes of the Wealth of Nations, Vol. 1, 1776, ch. 8