It was called 'The Second Man' with Jared as the amnesiac who hits his head and then starts taking care of an overworked Jensen and his mutlitude of siblings. There is also a diner where Jensen works and Jared tries to. It was utterly wonderful and now the journal has been purged and deleted. Ack! I can't remember the author, but if anyone has this on a pdf, or a link to an available online version somewhere, I would be forever grateful.