Once their was a boy living in an orphanage away from his parents and never got any sort of affection.
Another time, their was another boy who lived away from parents and he also never got any affection from anyone.
At the age of eleven, both escaped from their hell-like residents and found home in their boarding school.
Boy1 was charming, handsome and a favourite of his professors. Everyone wanted to be friends with him.
Boy2 wasn't so good-looking, but he was very famous and everyone wanted to be friends with him.
Both the boys were wizards, and boy2 was raised by non-magical people who had mistreated him all his life.
Boy1's father was non-magical and because his father had abandoned his mother, he grew up in an orphanage.
Boy1 grew up to hate non-magical people and those wizards whose both parents weren't magic. He destroyed them and was always hungry for power and immortality. Also, he never had any friends and treated everyone as an inferior. The only person he loved was himself.
Boy2 realised not all non-magic people are bad. He had the responsibility of saving the world and he gave his best. He was ready to walk to his death if that could save the world.
Boy1 was Voldemort and Boy2 was Harry Potter.
Rightly said, perspective matters!