So let's begin, with a postscript to a letter that Mark Twain sent to his brother on December 29, 1888. The letter was a tad intemperate, berating the brother for running through money like water and not following Twain's advice:
P. S. Don’t imagine that I have lost my temper, because I swear. I swear all the time, but I do not lose my temper. And don’t imagine that I am on my way to the poorhouse, because I am not; or that I am uneasy, for I am not; or that I am uncomfortable or unhappy—for I never am. I don’t know what it is to be unhappy or uneasy, and I am not going to learn how, at this late date.The letter, let us be clear, was absolutely brimful of swears.