Related:

• Never underestimate the power of human stupidity. -- Robert Heinlein, Time Enough for Love
• Never underestimate the power of human stupidity.
• The greatest productive force is human selfishness.
  -- Lazarus Long, from Robert A. Heinlein's "Time Enough For Love...
• Never frighten a little man. He'll kill you. -- Lazarus Long, from Robert A.
  Heinlein's "Time Enough For Love...
• Never try to out-stubborn a cat. -- Lazarus Long, from Robert A. Heinlein's "Time Enough For Love
• Never frighten a little man. He'll kill you. -- Lazarus Long by Robert A Heinlei
• What a wonderful world it is that has girls in it! -- Lazarus Long by Robert A Heinlei