It was worth adding delicious/poetry to my rss feeds just to be reminded of Piet Hein's Grooks. Picture swiped from here, where you can read a good brief biography.

ARS BREVIS

There is
one art,
no more,
no less:
to do
all things
with art-
lessness.

WHO IS LEARNED?
A definition

One who, consuming midnight oil
in studies diligent and slow,
teaches himself, with painful toil,
the things that other people know.

THE ROAD TO WISDOM

The road to wisdom? -- Well, it's plain
and simple to express:
           Err
           and err
           and err again
           but less
           and less
           and less.

HINT AND SUGGESTION
Admonitory grook addressed to youth.

The human spirit sublimates
the impulses it thwarts;
a healthy sex life mitigates
the lust for other sports.

ATOMYRIADES

Nature, it seems, is the popular name
for milliards and milliards and milliards
of particles playing their infinite game
of billiards and billiards and billiards.