Berra's Law
In theory there is no difference between theory and practice, but in practice there is.
(Yogi Berra, baseball player and manager)

Finagle's Law
If something can go wrong, it will go wrong, and at the worst possible moment.
(Finagle is a mythical follower of Murphy)

Gildin's Law
If it rhymes, it's true.
(Hilail Gildin, professor of philosophy at Queens College)

Herblock's Law
If it's good, they'll stop making it.
(Herbert Lawrence Block, political cartoonist for the Washington Post)

Hofstadter's Law
It always takes longer than you expect, even when you take Hofstadter's Law into account.
(Douglas Hofstadter, in his book Godel, Escher, Bach)

Mark Twain's Law
All generalizations are false, including this one.
Samuel Langhorne Clemens, aka Mark Twain, author)

Parkinson's Law
Work expands to fill the time available for its completion.
(C. Northcote Parkinson, historian)

Petronius's Law
Practice moderation in all things, including moderation.
(Gaius Petronius Arbiter, believed to be the author of the Satyricon)

Shaw's Law
The golden rule is that there are no golden rules.
(George Bernard Shaw, playwright)

Stigler's Law
No scientific discovery is named after its original discoverer.
(Stephen Stigler, statistician, who stated that this law was discovered by the sociologist Robert K. Merton)

Sturgeon's Law
Ninety percent of everything is crap.
(Theodore Sturgeon, science fiction author)

Wilde's Law
Everything popular is wrong.
Oscar Wilde, author

Wirth's Law
Software gets slower faster than hardware gets faster.
(Niklaus Wirth, computer programmer)