Murphy's Laws (as posted in Arizona Humor)

Murphy's First Law: Nothing is as easy as it looks.

Murphy's Second Law: Everything takes longer than you think.

Murphy's Third Law: In any field of endeavor, anything that can go wrong will go wrong.

Murphy's Fourth Law: If there is a possibility that several things can go wrong, then the one that will cause the greatest damage will be the one to go wrong.

Murphy's Fifth Law: If anything absolutely can NOT go wrong, it will anyway.

Murphy's Sixth Law: If you perceive that there are four possible ways in which a procedure can go wrong and circumvent these, then a fifth way, unprepared for, will promptly develop.

Murphy's Seventh Law: Left to themselves, things tend to go from bad to worse

Murphy's Eighth Law: If everything seems to be going well, you have obviously overlooked something.

Murphy's Ninth Law: Nature always sides with the hidden flaw.

Murphy's Tenth Law: Mother Nature is a son-of-a-gun.

Murphy's Eleventh Law: It is impossible to make anything foolproof, because fools are so very ingenious.

Murphy's Twelfth Law: Things get worse under pressure.

A few additions to Murphy's Laws ...
-To study a subject best, understand it thoroughly before you start.
-If an experiment works, something has gone wrong.
-If mathematically you end up with the incorrect answer, try multiplying by the page number.
-When in danger or in doubt, run in circles, scream and shout!