The wisdom of grooks . . .

     From Wikpedia, we have this definition:       A grook ("gruk" in Danish) is a form of short aphoristic poem or rhyming aphorism, created by the Danish poet, designer, inventor and scientist Piet Hein (1905-1996), who wrote over 7000 of them, mostly in Danish or English. A couple mathy grooks are offered below -- and, below them, links to more.

        PROBLEMS          by Piet Hein

Problems worthy

of attack

prove their worth

by hitting back.

The grook shown above and more are found here:

     SIMILARITY     by Piet Hein

Commutative Law

No cow's like a horse,

and no horse like a cow.

That's one similarity

  anyhow.

The latter grook above, along with others, may be found here.   And still more grooks appear in this blog posting from several years ago.