Me Again (джен)

In your research, you’ve determined that there’s not many possible answers to your problem. You’ve narrowed it down to four options.
1. You’ve been possessed by a ghost.
2. You’ve hit your head really hard, and you’re starting to hallucinate.
3. Someone’s cursed you to slowly drive you insane.
4. Your past life has decided it's not staying in the past anymore.
You have a sneaking suspicion it’s the last one. In a few of your new memories, you see the founding of Hogwarts, and with that, your connection to the castle—your thoughts are briefly interrupted by a mental pat from said castle—so there’s only four people you could be. And though you still don’t remember everything, you somehow doubt that the other Founders liked snakes.
or,
Harry Potter is Salazar Slytherin. Or rather, Salazar Slytherin is Harry Potter.