You pull to the side of the road and get out, hoping for a view of the avian example before you. He's black, feathery, and looks rather like a bird. He looks up at you, locking eyes, and says, "How am I like a writing desk?" You take a moment to consider the question while you formulate your reply. You could swear you'd heard somebody ask it before, but what a puzzling question: how is a raven like a writing desk?