Thank you, John, for such high, but I am afraid overgenerous praise.
I have read of musicians who survived years extermination camps where they reworked their interpretations of sonatas (all in their heads, of course–no pianos for untermenschen). Churchill recited all of Horatius at the Birdge at some point I think in WW II, not having read it since he was a boy.
Henry Clay, by contrast, could not quote poetry and mangled the simplest Shakespearean allusions–an interesting failing considering his eloquence, which was universally acknowledged. Something to do with narcissism perhaps.
Poetry (and music) must be easier to remember than prose. I wonder if there are tests which show this.