a cervantes riddle:

dark 'tis, yet very clear,
containing infinite variety,
encumbering us with truths,
which are at length declared.
'tis sometimes of a jest produced,
at others of high fancy.
and it is wont defiance to create,
of airy matters treating.

any man its name may know,
even to little children,
many there are, and masters have
in different ways.
there is no old woman it embraces not,
with of these ladies, one
at times in good odour,
this tires, that satisfies.

wise ones there be who overwatch
sensations to extract.
some run wild
the more they watch o'er it.
such is foolish, and such curious,
such easy, such complex,
yet, bet it something, be it nought, 
reveal to me what the said thing may be?


      -  from cervantes, book 6 la galatea.