You will encounter someone who sees something you don't.  You may encounter a Feynman.  If you teach, you'll occasionally encounter a student who sees something you are missing, even in your own field.  Occasionally Feynman looked absurd to someone.  ("Feynman wasn't a misogynist; he could be rude to anyone," was a recent comment in Physics Today.)

However, we can make a list of useful rules to keep our silliness at a minimum.  Here's a start:
 

Don't use science to "prove" some far-out hypothesis when you can't use the same science to solve problems it was originally built to solve.

      For example, don't use quantum mechanics or special relativity to prove Uri Geller can mentally bend spoons if you can't successfully apply quantum mechanics to S = k ln W to calculate entropy or use E=mc² to calculate the free energy yield of a nuclear explosion without knowing the anticipated change in rest mass.  

Be able to recognize the distinction between a representation and what it represents.

      For example: the independent variables in an algebraic equation represent sets of numbers that get operated upon as the equation describes.  Words, like "energy" and "implication" represent sets of experiences, observations, concepts, constructs, mental models, etc, which get woven into theories that help us anticipate outcomes of actions we might take.  Money represents value, but is not the same thing.

Learn to use statistical reasoning.

      For example, become able to see how "expectation value" predicts return in gambling, and learn how to assure that you win in the long run.  Become able to see how random fluctuations affect, microscopically, numbers that can, nevertheless, be predicted macroscopically.

Acquire a sense of "self-deception."

      For example, become aware of biases to believe, and how they can distort apparent statistics.  Acquire resistance to belief in anything that has little more substance than its desirability.  Acquire faith in reason.

Don't shirk hard work.

     For example, before starting a journey of understanding of elementary physics, understand acceleration to at least the depth necessary to "see" the direction of acceleration of the ball as it bounces off the surfaces of the handball court. An understanding of the simple "p" test of statistical significance is necessary before we state with certainty that the board-certified internist was wrong, and the naturopath was right when he claimed that the juices in the root of Conium maculatum cured our intractible indigestion.                Understanding comes best from experience.  Socrates understood, through experience, how Conium maculatum cures intractable indigestion.  Permanently.  Conium maculatum is the poison hemlock by which Socrates was executed.
Learn, as Socrates understood we must, by discovery.