It sometimes happens at the end of a dinner, when jokes and walnuts are cracked together, that the paternity of some trite quotation is put in question, and at once the wit of the whole company is set wool-gathering. – Frederic Swartwout Cozzens, “Phrases and Filberts,” Sayings, Wise and Otherwise

I often quote myself. It adds spice to my conversation. – George Bernard Shaw

I am now to offer some thoughts upon that sameness or familiarity which we frequently find between passages in different authors without quotation. This may be one of three things either what is called Plagiarism, or Imitation, or Coincidence. – James Boswell, “The Hypochondriack,” No.XXII, 1779