 This is a temporal difference case: there’s an important doxastic difference between the professor when he’s sitting motionless in his office, thinking to himself “the meeting begins at noon”, and the professor when he starts to move, thinking to himself, “the meeting begins now”. But the difference isn’t in traditional propositions believed—the professor believes, both before and after he begins to move, that the meeting begins at noon, at the time when the clock strikes twelve times, etc. Characterizing the difference requires resources beyond those of the Simple Picture.