Murphy's Law...

Murphy's Law

"If anything can go wrong, it will go wrong."

"Murphy's Law" can be traced back to Captain Edward A. Murphy,
an American engineer at Muroc, California (later named Edwards Air
Force Base). In 1949 he was working on a project to test the effects
of sudden braking. Time after time his machinery failed. Exasperated
he said of his technician, "If there is any way to do it wrong, he'll
find it." John Paul Stapp picked up on Murphy's phrase and used it at
a press conference.

As with any good idea, Murphy's Law can be adapted and extended.

1st Amendment
If there is a possibility of several things going wrong, the on that
will cause the most damage will be the one to go wrong.

2nd Amendment
If you realize that there are three possible ways in which something
can go wrong, and cover them all, then a fourth, unprepared for way,
will miraculously appear out of thin air.

3rd Amendment
When something breaks, the parts damaged are in direct proportion
to their value.

4th Amendment
The failure does not appear until the machinery has passed its
final inspection.

5th Amendment
When you drop a part, it always rolls into the darkest corner.

Last Amendment
Any attempt to print out this copy of Murphy's Law will crash
your computer.

Examples of Murphy's Law:

1. Your lost needle will be found by your husband when he is walking
around barefoot.
2. The worst pupil in any class will be a school governors' son.
3. Uniforms only come in two sizes, too large and too small.
4. Vital documents that were posted with no errors,
will develop errors in the mail.
5. The other queue always moves faster.
6. In order to get a bank loan, you must first prove that
you don't need the money.
7. The classic example of Murphy's law: If you drop a piece of
toast it always falls buttered side down.


Source and to read more:
Will and Guy's Humour