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• The more right one is, the more careful he should be to express his opinion tactfully.
  The other fellow never likes to be proved wrong. -- John Luthe...
• He who has an opinion of his own, but depends on the opinion and tastes of others is a slave.
  -- Klopstock...
• Murphy wasn't an optimist. He just got it wrong.
• If it's not mathematics, it's just opinion.
• He's like a function -- he returns a value, in the form of his opinion.
  It's up to you to cast it into a void or not. -- Phil Lapsley...
• He may like to go alone for a walk, but he hates to stand alone in his opinion. -- George Santayana
• I will fight for your right to your wrong opinion.
• You're entitled to your opinion. Wrong - but entitled.
• You're entitled to your own opinion, even if it is wrong.