1. Light travels faster than sound.  This is why some people appear bright until you hear them speak.
2. Change is inevitable, except from a vending machine.
3. Those who live by the sword, get shot by those who don't.
4. Nothing is foolproof to a sufficiently talented fool.
5. The 50-50-90 rule: Anytime you have a 50-50 chance of getting some thing right, there's a 90% probability you'll get it wrong.
6. If you lined up all the cars in the world end to end,  some one would be stupid enough to try to pass them,  five or  six at a time, on a hill, in the fog.
7. The things that come to those who wait will be the scraggly junk left by those who got there first.
8. The shin bone is a device for finding furniture in a dark room.
9. A fine is a tax for doing wrong.    A tax is a fine for doing well.
10. When you go into court, you are putting yourself into the hands of 12 people who weren't smart enough to get out of jury duty.

My personal favorite is

"Nothing is foolproof to a sufficiently talented fool."