On the night of November 1, 1981 most of the Wizarding World of Britain was celebrating. They were celebrating the fall of the most powerful Dark Lord of the last 500 years. They celebrated, cheering the Savior of the Wizarding World. But not once during their celebrating did they think about the price a young baby had to pay so they could have peace.
Not once did they think about the little orphan who was being left on the doorstep of a family who didn't want him. Not once did they think that that little boy had lost all of his family that night.
It was on that night that Albus Dumbledore left the little orphan on the doorstep of his aunt's home. Albus Dumbledore, who was considered by many as the greatest wizard since the Founders of Hogwarts, was confident that he had made the right choice. They were, after all, the boy's family. It was best if he grew up away from all the fame that he was certain to receive, so that when he finally went to Hogwarts it would be easier to guide him in the right direction, because the boy would not have been subjected to the bigotry of the wizarding world. In all his wisdom he saw no problem with his plan, in his opinion there was no way it could go wrong.
It would take ten years for Albus Dumbledore to start to understand how wrong his plan would go, and a few more after that for him to really see just how wrong he was when it came to dealing with the young Harry