"there is nothing more deceptive than an obvious fact," he answered, laughing. "besides, we may chance to hit upon some other obvious facts which may have been by no means obvious to mr. lestrade. you know me too well to think that i am boasting when i say that i shall either confirm or destroy his theory by means which he is quite incapable of employing, or even of understanding. to take the first example to hand, i very clearly perceive that in your bedroom the window is upon the right-hand side, and yet i question whether mr. lestrade would have noted even so self-evident a thing as that."