Tom Marvolo Riddle always had a penchant for stealing others' playthings. It started with yo-yo's and seashells and matchstick dolls. It manifested in the death of a beloved pet and the silencing of two orphans.
When he reached Hogwarts, he learned that wearing a charming face got him more than being obviously cruel. So then, he took to stealing thoughts and attention and hooded looks across bustling halls and dimly lit common rooms.
From girls too charmed to believe and boys too jealous to notice, he stole more than chocolate frogs and trading cards. Tom Riddle stole the hearts of professors and students alike. He stole the brightest minds of his time and twisted them into extremist supporters of a half formed dream.
He stole innocence and sanity and lives. He snatched away his own humanity and did not understand what he'd done until the concept of regret was far from his reach.
As a child, when Tom Riddle stole something, the other orphans would try to take it back, afraid that he—in his madness—would taint it. When Voldemort had stolen something, no one wished it back because they did more than fear. They knew he'd tainted it.