Related:

• Never underestimate the power of human stupidity. -- Lazarus Long by Robert A Heinlei
• 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
• Belief gets in the way of learning. -- Robert Heinlein, Time Enough for Love
• Anyone who cannot cope with mathematics is not fully human.
  At best he is a tolerable subhuman who has learned to wear shoes, bathe and not make messes in the house....