Please Remember (APH-USUK/HP cross-over) (UNFINISHED)

Arthur can't remember his first year at Hogwarts, spent his second catching up, and his third alone. Now, during his fourth year, someone comes into his life claiming that they were a part of his forgotten year. But how can he trust someone who has had this knowledge for three years and kept it to themselves? And a Gryffindor at that!