I had the great good pleasure of hearing Billy Collins read poetry and discuss poetry, twice, in the last 24 hours. I am, unfortunately, not able to quote this exactly because I thought I could come home and look it up, but apparently, not everything everyone has ever said is on the internet.
Mr Collins was quoting Kenneth Koch (I believe. I know I have the last name right because he spelled it for me) on the difference between poetry and prose.
Mr Koch said "No dogs on the beach - now that is prose.
No dogs, or logs, on the beach.
No poodle, however trim.
No dachshund, unable to swim.
Now that is poetry" and Mr Collins elaborated. "It is poetry because the words in the poem are playing with each other, with sound, and rhythm and structure."
They bounce around each other, and become more robust because of who they are with.
I didn't want to forget this.