Dursley's Ugly Behaviour Might Have Been Harry Potter's Fault All Along
Maybe the Dursleys were the victims after all?
Among the many theories, there is one that justifies the Dursley family's terrible parenting methods. The fact is that they fell under the bad influence of... Harry Potter.
And this is explained in a pretty logical way — by the dark magic of Horcruxes.
We know that Harry was accidentally turned into the Horcrux when Voldemort destroyed himself with a killing curse.
A tiny piece of Tom Riddle's soul entered Harry and remained there for the next 17 years. Despite the fact that Harry was an unusual Horcrux, we know that Voldemort's presence had an effect on him, giving him some powers like the ability to understand and speak Parseltongue.
However along with these benefits he also received bouts of anger and aggression. What if Harry wasn't the only one negatively affected by Voldemort's unseen presence?
There is much information in the books that Voldemort's Horcruxes were capable of permanently altering the personality of the Horcrux bearer.
Remember how the Slytherin Locket affected the trinity? Or how Tom Riddle's diary took over Ginny's mind in just one school year? Now imagine how the Horcrux affected the Muggle family for ten years.
Whether magical items affect Muggles in the same way as wizards, we don't know for sure. But we can assume that they do, and to a greater extent.
Maybe that's why Harry never got along with his family? And we haven't heard anything about his friends in the Muggle world, or couldn't he make any in eleven years? We wonder why...
The effect of magical objects on Muggles could explain why Potter had no particular problems communicating at Hogwarts: everyone there was a wizard. Well, except for the caretaker Filch, who did not like him either.
If the Horcrux can influence good people in such way in a short period of time, we feel sorry for the Dursleys who had to spend ten years around it.
Of course, in hindsight, we know that both Petunia and Vernon were quite evil as children, but the Horcrux may have blocked their ability to improve. So maybe the Dursleys deserve pity, not contempt.