Explaining Murphy's Law!

At this time of year an Irish theme
Springs to mind, deep emerald green;
The four-leaved clover is a token
Of St. Patrick we have spoken.

What of James Joyce and Seamus Heaney
Powerful authors and both “greeny”
And celebrated Oscar Wilde
A brilliant writer, but defiled?

Who tops this modest list of mine?
Your friends have met him, so have mine
He spans the centuries unscathed
His Law survives beyond the grave!

Old Murphy realised long ago
How human plans are flawed and slow
No air-tight project can we spawn
But is foiled by Murphy's Leprechaun!

(c) Poet in the woods 2015