Melanie shared a link on Facebook about how memorizing poetry was a great thing to do, and there was a discussion which got somehow into unintentionally memorized poetry. I've done lots of on-purpose memorizing, as remembering words in rhythmic patterns is one of my weird abilities. So, I know lots of Eliot, some Auden, Dylan Thomas, a scattering of Romantic poets and some Dickinson. A couple of Donne, since Judith and I did one of his sonnets for Lent last year (Thou Hast Made Me/And shall Thy work decay).
I know a bunch of things incompletely, like parts of A Child's Christmas in Wales and parts of The Dry Salvages. I used to know the first two Quartets in full, but they're slipping without regular recitation, and my kids haven't shown a whole lot of enthusiasm for Eliot yet. Geoff did The Raven and The Love Song of J. Alfred a few years back, and I learned parts listening to him.
As I said, I just sort of remember things that rhyme, and because of that I have a whole bunch of bad poetry from Anne McCaffrey's Pern books lodged permanently in my head. I think I learned the In the Land of Mordor... bit from LotR years before I read them, because I liked the entry in The Dictionary of Imaginary Places. I will always have most of the prophecies from Susan Cooper's The Dark is Rising in my subconcious.
It's the Pern poetry that bothers me most, because, well, it's bad, and it's always just sort of there, humming "Gone away/Gone ahead/ Why have all the weyrfolk fled?" in the back of my head. Like Eighties commercial jingles that you can still hear in your mind at one at night when you're trying to sleep.