I watched the third Harry Potter movie last night. HP3 (and HP6) are my favorites in the series. In HP3, I love how time plays into so much of the plot. Besides the time turner, the patronus charm and dementors both derive their power from memories, happy and sad respectively. What if those memories became recursive? Could you produce a patronus if the memory you had in your head was the first time you cast a patronus? Could a dementor haunt you with the memory of the first time you saw a dementor?