Praeclarus Anguis

“Tell me Harry, if I were to tell you that you could go back in time and prevent one event of your choice from ever occurring would you do so?”
Go back in time? A chance to change the past for a better future? “If such were possible, Sir, I think it’s safe to say most people would.”
“Would you be an exception?” Harry shook his head. “What would you change?”
His immediate knee jerk reaction was that he’d go back to that horrible night in Godrick’s Hollow and prevent the murder of his parents, but when he opened his mouth to speak he stopped abruptly. The Head Master was staring at him from behind his half-moon glasses in a way that made him think that this question was in itself a sort of test. And with more examination the prospect seemed a bit selfish.
At once Harry knew what he would do. “I would stop Tom Riddle from ever becoming Voldemort.”