Also, its not that good of a model. The best way to learn is "without error". Learning by trying will let you practice and maybe learn the poem, but after a while, when you want to remember it, you will make errors with the errors you made before (by taking guesses). The brain works with association, you will remember your errors too, which is bad.
David Gourde about Poems By Heart from Penguin Classics, v1.1