Disclaimer: I don't own Harry Potter.
It's often the little things, thepetty injuries that warp people. With big things ... you learn how to cope. You have to. But with every little insult, every little rejection, you begin to wonder if maybe you deserve it, if maybe you are as worthless as they seem to think. And once you begin to think that you're no good, you tell yourself that trying to be good doesn't matter, and you can just do as you wish, and avenge yourself on those who have wronged you. And they don't even realize why they will suffer, because their slights were from carelessness and indifference, not cruelty and malice. And they called themselves your friends, but you knew that they only thought of you as a sycophant, not as a real person with real feelings. And the knowledge of what they think is like acid in your veins, driving you forward to fantasies of greater and greater cruelty. But you always thought they would be just that, fantasies, until someone made you an offer. And you accepted, and bided your time, and played the good little suck up, until they delivered themselves into your hands. And tonight, October 31st 1981, all wrongs done you, Peter Pettigrew, will be revenged.