Writing poetry is
digging a hole in the ocean,
shovelful by shovelful,
word by word.
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Digging a hole in the ocean with a shovel is impossible.  I know.  I tried it as a kid on the beach at Montauk Point, Long Island. Every shovelful of water taken out was instantaneously replaced by water rushing in.  The project was a failure.  Poets sometimes feel that way about poems.  Try as you might to get something well said, you realize there are many ways to say it differently and some of them are better.  One could rewrite the same poem every day and every day create a different poem.  So the poet stops and moves on to the next constellation of events that arrives in his or her experience.  As the French poet and critic Paul Valery (1871-1945) wrote:

“A poem is never finished, only abandoned.”