Poems You Can Only Get Away with Once

Some poems are delightful because they are witty little things that cannot be repeated. (Mmmh--can any poem be repeated? Then why do these type I'm thinking of seem especially unrepeatable?) Here's an example by Desmond Skirrow:

Ode on a Grecian Urn Summarized

Gods chase.
Round vase.
What say?
What play?
Don't know.
Nice, though.