Reminds me of the elevator button example:<p>You're in the fourth floor, the elevator is on the fifth floor (indicated by a display above the door) and you want to go up.<p>Do you press the <i>up</i>, or <i>down</i> button?<p>At first this seems obvious, since you want to go up, but it's only obvious because you know how elevator interfaces work.<p>Another valid way to interpret the elevator interface is to press the down button, since you're in the fourth floor and want it to come down to you.<p>Yep, interface design is hard.