It is for a reason of the same kind, that a certain reserve is necessary when we talk of our own friends, our own studies, our own professions. All these are objects which we cannot expect should interest our companions in the same degree in which they interest us. And it is for want of this reserve, that the one half of mankind make bad company to the other. A philosopher is company to a philosopher only; the member of a club, to his own little knot of companions.
~ Adam Smith (1759) The Theory of Moral Sentiments, 33-4