Never bet on a loser because you think his luck is about to change.
Never buy from a rich salesman.
Never do anything you wouldn't be caught dead doing.
Never do card tricks for the group you play poker with.
Never eat prunes when you are famished.
Never get so busy making a living that you forget to make a life.
Never go to a doctor whose office plants have died.
Never insult an alligator until after you have crossed the river.
Never invest in anything that eats.
Never kick a man unless he's down.
Never leave hold of what you've got until you've got hold of something else.
Never needlessly disturb a thing at rest.
Never offend people with style when you can offend them with substance.
Never play leapfrog with a unicorn.
Never put all your eggs in your pocket.
Never put off until tomorrow what you can do today. There might be a law against it by that time.
Never say “oops” after you have submitted a job.
Never sleep with anyone crazier than yourself.
Never tell them what you wouldn't do.
Never try to pacify someone at the height of his rage.
Never underestimate the power of human stupidity.
Never volunteer for anything.
Never wrestle a pig； you both get dirty， and he likes it.
Nice guys finish last but it is lonely at the top.
No experiment is ever a complete failure； it can always be used as a bad example.
No good deed goes unpunished.
No man is lonely while eating spaghetti.
No man's credit is as good as his money.
No matter how much you do， you'll never do enough.
No matter what happens， there is always somebody who knew that it would.
No matter which direction you start， it's always against the wind coming back.
No matter which way you go， it's always uphill and against the wind.
No one is listening until you make a mistake.
No problem is so formidable that you can't just walk away from it.
No real problem has a solution.
No two identical parts are exactly alike.
Nobody notices the big errors.
Nobody notices when things go right.
Nobody wants to read anyone else's formulas.
Nobody told me.
Nostalgia isn't what it used to be.
Nothing astonishes men so much as common sense and plain dealing.
Nothing can be done in one trip.
Nothing ever comes out as planned.
Nothing is as easy as it looks.
Nothing is as inevitable as a mistake whose time has come.
Nothing is as permanent as that which is called temporary.
Nothing is as temporary as that which is called permanent.
Nothing is ever accomplished by a reasonable man.
Nothing is ever as simple as it seems.
Nothing is impossible for the man who does not have to do it himself.
Nothing matters very much， and very few things matter at all.
Nothing puzzles me more than time and space； and yet nothing troubles me less.
Of all forces acting on man， change is the most beneficial and the most cruel.
Of two possible events， only the undesired one will occur.
Office Of Precision Guesswork
Old age and treachery shall overcome youth and skill.