“Knock yourself out... Or rather, don't.”
“Knock yourself out.”
“And tell your wife whatever you want, but don't make promises you're not going to keep. And don't knock yourself out over it; you didn't invent infidelity.”
“No man ever got very high by pulling other people down. The intelligent merchant does not knock his competitors. The sensible worker does not work those who work with him. Don't knock your friends. Don't knock your enemies. Don't knock yourself.”
“The world will knock you down plenty. You don't need to be doing it to yourself.”
“Do not think of knocking out another person's brains because he differs in opinion from you. It would be as rational to knock yourself on the head because you differ from yourself ten years ago.”