Da Law.

I happened to look up Murphy's Law the other day. Interesting stuff. Here's the origin of Murphy's Laws:

[Murphy's Law] was named after Capt. Edward A. Murphy, an engineer working on Air Force Project MX981, designed to see how much sudden deceleration a person can stand in a crash.

This website has a complete listing of Murphy's Laws. My favorite is #6:
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.

And... if you scroll down the site, you will find other laws. For example:

Allen's Axiom
When all else fails, follow instructions.

Barrett's Laws of Driving:
You can get ANYWHERE in ten minutes if you go fast enough.
Speed bumps are of negligible effect when the vehicle exceeds triple the desired restraining speed.
The vehicle in front of you is traveling slower than you are.
This lane ends in 500 feet.

Cohn's Law:
The more time you spend in reporting on what you are doing, the less time you have to do anything. Stability is achieved when you spend all your time doing nothing but reporting on the nothing you are doing.

Fett's Law of the Lab:
Never replicate a successful experiment.

Ginsberg's Theorem (Generalized Laws of Thermodynamics):
You can't win.
You can't break even.
You can't even quit the game.

Herblock's Law:
If it's good, they'll stop making it.
***The Testerman Corollary: ...but not until after you've started watching the first season.

Issawi's Law of Frustration:
One cannot make an omelette without breaking eggs -- but it is amazing how many eggs one can break without making a decent omelette.

Laura's Law
No child throws up in the bathroom.

Lawyer's Rule
When the law is against you, argue the facts. When the facts are against you, argue the law. When both are against you, call the other lawyer names.

Martha's Maxim (and see Olum's Observation and Farrow's Finding):
If God had meant for us to travel tourist class, He would have made us narrower.

Margaret Mead's Law of Human Migration:
At least fifty percent of the human race doesn't want their mother-in-law within walking distance.

Ozian Option:
I can't give you brains, but I can give you a diploma.

Let me try some:

If the milk has gone bad, someone will ask you to taste it to make sure.

Rules of Colorado Driving:
1. It's always a good time to change lanes.
1a. Use as many lanes as necessary.
2. It's not running a red light if you gun your engine first.
3. If one lane is full of cars and the other is empty, take the full one.
3a. See Rule 1.