I know this is just a fan theory, but after reading it, you’ll have to wonder if this is what was in J.K. Rowling’s head when she wrote Harry Potter. As most of us know, Harry’s foster family, his Uncle Vernon, Aunt Petunia, and cousin Dudley, were more than a little miserable to their charge over the entire time they had him in their custody. In fact, they were downright abusive, and seemingly for no reason other than maybe Petunia’s resentment that her sister, Lily (Harry’s mother) was murdered and Harry survived. But one fan proposed a theory on Tumblr that might explain everything, and it’s pretty damn good.
Hold on to your Sorting Hats, this is a doozy, like when we learned that Ariel from The Little Mermaid totally could have written letters to Prince Eric explaining her conundrum the whole time she was mute.
Harry was a horcrux since the day he was struck by Voldemort as a baby and got that lightning scar. What do horcruxes do? They make people pissy. They make good people evil and evil people stronger. But I’ll let the intrepid Potterhead explain:
…[T]he Dursleys were just minding their own business when a horcrux was dumped on their doorstep. For the next decade it proceeded to warp their minds, turning them from your garden variety insufferable human beings into horrible, heartless monsters. The fact that they survived such prolonged horcrux exposure without delving into insanity or abandoning a helpless child only solidifies their place among the pantheon of noble and virtuous heroes in the Harry Potter universe.
If this is true, then this could probably mean that Petunia willingly took her nephew into her custody after Lily and James were killed with nothing but the best intentions. For all we knew, Vernon adored Harry at first, too, but having a horcrux in the house — and in an infant, no less, who needed such hands-on care — could have totally driven that family bonkers.
That is one wicked theory. I’m making it true in my head canon.