Just because you’re paranoid doesn’t necessarily mean they’re not out to get you.
What I told students about weather decisions. I always applied it to my weather decisions too.
“Tis better to be down here wishing you were up there than being up there wishing you were down here.” 
When you open the door to violence, don’t be surprised that more walks in than you expected.
Don’t make it my problem (used when someone says “What should I do about this?”)
Don’t compare how you feel on the inside to how someone else looks on the outside.
Is it not written I feel sorry for all you muggles who don’t follow The Way Of Mrs Cosmopilite?
“Whoever believes they have made something foolproof has failed to account for the ingenuity of fools.”
“There is no problem so bad that it cannot be made worse through brute force and ignorance.”
And, as I often tell my boss, “I have no problems a big check (or large amount of money) won’t fix.”
Just because a dream ends, doesn’t mean it didn’t come true.
If you know what you’re doing, it’s not an adventure.
Spend as much time as you can with the nice people, because it barely begins to make up for all the time you have to spend with the assholes.
I was a production supervisor, fond of
Excuses don’t pay the rent
on the graveyard shift,
If that ain’t funny, you must be getting enough sleep
And valuable wisdom from some odd one-legged flute player,
Show a little pride before you fall
Always start everything you finish.
Try to stay in the same line of business your boss is in.
“A hard man is good to find.”
– Seen on front of female shift supervisor’s shirt, circa 1977.
Here’s a well-known one:
“No amount of planning can take the place of dumb luck.”
One supervisor I had (not the same one with the hard man shirt), a native of Holland, had a bumper sticker on the wall of her office with this in Dutch.
Un bon mot ne prouve rien. - A witty saying proves nothing.
Knoll’s Law of Media Accuracy (Erwin Knoll, editor, “The Progressive”):
Everything you read in the newspapers is absolutely true—except for the rare story of which you happen to have firsthand knowledge.
Voltaire wrote that in Le dîner du comte de Boulainvilliers (1767): Deuxième Entretien.
Yep. I heard it as “Experience is what you get when you don’t get what you want”
If you torture data sufficiently, it will confess to anything.
Any sufficiently advanced stupidity is indistinguishable from malice.
In every society, every generation is faced with an invasion of barbarians - we call them “children”.
Life is just like High School. The only difference is that it’s not over in 4 years.
Sex is much too important an activity to share with someone else.
Meditation-- it’s not what you think.
Sometimes it’s better to be lucky than good.
I have a similar version I tell my kids: “Adulthood is just high school with better liquor.”
Saw this sign on my wife’s desk and I kinda like it: “Be brief, be bright, and be gone.”
Along those same lines:
“It’s not the things we do in life that wear us down, it’s the things we don’t do.”
Cree el ladrón que todos son de su condición - a thief believes everybody is out to steal. We do tend to assume that others are like us, so if someone’s first assumption is that people shouldn’t be trusted, do assume that particular someone should not.
Tanta alforja para tan poco viaje - much ado about nothing. A reminder to not put more effort into things than they are really worth. Close relative to KIS.