David Taylor - The Cup

He looked deeply in his cup
and thought it's only half full up
but when he looked within
he found it filled up to the brim
the empty space was occupied
by all the things that he desired
and left no space or gave room
for any wisdom to reside
and tell him what he needs to know
a cup that's not full up to the brim
is much more useful inside him.

David Taylor

http://www.poemhunter.com/poem/the-cup-5/