[gruseom]

They're tricks, but they're far from incomprehensible. In my experience, both with this sentence and the buffalo one, there's a certain mental click when one "gets it", after which the sentence makes sense and one can "feel" its grammatical structure. It's a curious and rather Chomskyan experience. Before that, of course, the notion that such a string of words might mean anything is absurd. "Getting it" is much like those 3D visual puzzles where at first you see only a noise pattern, but when you hold it at the right distance and let your eyes refocus a certain way, a picture leaps out at you.