Murphy’s Law

Funny... every time I rethink your question, I flip flop on my answer. My gut tells me it IS an incorrect usage but I cannot pin down why. Murphy basically said "whatever can go wrong will." I think we don't usually apply that to human nature, maybe, but to things that happen to people. I am in a hurry to get somewhere and traffic is bad, the drawbridge opens unexpectedly, and my car overheats. Murphy's law. My boss makes me work late which is why I am in hurry which he always does on days I have to be somewhere after work. Not Murphy's law.

Murphy's Law is literally, "If anything can go wrong, it will."

Who, exactly, was Murphy?

Murphy's Law, as I understand it, is something that you can't control, not something resulting from a choice you make. In the case you mention it is your decision to increase or not, it is not something that happens by "nature".
It's not just inclining towards the worst case scenario, it's a worst case scenario beyond human control...

The second case mentioned by janet is more "Boss Law" than Murphy's Law

Murphy is everybody, of course... the average man...

Not Murphy's Law, but Parkinson's Law: Work expands to fill the time (or space)allotted for it.
C. Northcote Parkinson, who wrote the book.

Oh, there WAS a Murphy! The version of the Law I gave below is its popularization. See this page for details: http://www.cpuidle.de/murphy.shtml

Of COURSE there was a Murphy, but he didn't postulate the answer to Dyske's Dilemma. Parkinson did.

What you have called "the Murphy's Law of something", others would call a dilemma or a catch-22. One who makes such a choice is damned if he does and damned if he doesn't.

What I would call "Murphy's Law" is merely "whatever can go wrong, will".

Submitted for your amusement, the first 26 catches of the catch list:

Catch Code
26 - Catch Your Favorite Soap Opera
25 - To Catch All
24 - A Wild Catch
23 - To Claim You Caught the Uncatchable
22 - To be caught if You Do, or Do Not
21 - A Prized Catch
20 - To Catch Up
19 - Catch Me if You Can
18 - The Catch of the Day
17 - The Miraculous Catch of Fish
16 - A Fair Catch
15 - Catch and Release
14 - What's the Catch?
13 - To Catch Fire
12 - To Catch a Rising Star
11 - To Catch Anything
10 - To Catch Some Shut-Eye
9 - To Catch your Breath
8 - To Catch One is as good as Catching All
7 - Catch them While You Can
6 - To Catch a Glimpse Of
5 - To Catch a Thief
4 - Catching the Wind
3 - Catching the Chicken
2 - A Good Catch
1 - Catch a Break
0 - Catch you later

There's a list? Awesome.

I bet it's in the book... I never got around to reading the book, actually. :(

Your example was incorrect. As Janet says, the general Murphy's Law definition is: Whatever can go wrong, will.

If you filled your computer with all sorts of useless info and then your whole system crashed before you could back it up, that would be Murphy's Law.

It's not Murphy's Law if you fill up your space because the space happens to be there.

Similarly, if I eat and eat and eat until I'm obese, that is not Murphy's Law. Since I did it to myself nothing technically "went wrong."

If I'm fit and thin but die of a heart attack while running, that might be Murphy's Law.

Your use of the definite article is incorrect. "Murphy's Law"" is equivalent to "the Law of Murphy", therefore "the Murphy's Law" contains an implicit reduncancy, since it would be equivalent to "the the Law of Murphy".