In the Harry Potter books, young witches and wizards who haven’t started learning magic yet often produce it without realizing exactly what they’re doing. Sometimes, it’s simple magic, like making flower petals open and close, or re-growing hair after an embarrassing haircut. However, sometimes young children produce magic that even adult wizards have trouble with. For example …
“The girl had let go of the swing at the very height of its arc and flown into the air, quite literally flown, launching herself skyward with a great shout of laughter, and instead of crumpling on the playground asphalt, she soared like a trapeze artist through the air, staying up far too long, landing far too lightly” (Deathly Hallows 663)
While levitating objects is one of the first things Hogwarts students learn to do, levitating oneself is much more difficult. Very few wizards are capable of flying without a broom; only Voldemort and Snape are shown to do so, and everyone seems shocked that they can. And yet, young Lily Evans could already do something very similar.
“Dudley’s gang had been chasing him as usual when, as much to Harry’s surprise as anyone else’s, there he was sitting on the chimney. The Dursleys had received a very angry letter from Harry’s headmistress telling them Harry had been climbing school buildings. But all he’d tried to do (as he shouted at Uncle Vernon through the locked door of his cupboard) was jump behind the big trash cans outside the kitchen doors” (Sorcerer’s Stone 25)
Apparition is like the wizarding equivalent of driving a car. You have to pass a test and get your license before you can do it outside of class, and you can’t take the test until you’re seventeen. And yet, that’s almost definitely what Harry did here. One minute, he’s trying to get away from Dudley’s gang, and the next, he’s magically disappeared and he’s up on the roof. Probably lucky he didn’t splinch himself, apparating without a clear destination in mind.
“One second, Piers and Dudley were leaning right up close to the glass, the next, they had leapt back with howls of horror. … The glass front of the boa constrictor’s tank had vanished” (Sorcerer’s Stone 28)
While not as extreme as some of the other examples, vanishing spells are not taught until fifth year at Hogwarts, and most of the students seem to have difficulty with them. Harry, just before his eleventh birthday, is able to vanish an enormous pane of glass. Of course, he doesn’t know what he’s doing yet.
“I can make animals do what I want them to do, without training them. I can make bad things happen to people who annoy me. I can make them hurt if I want to” (Half-Blood Prince 271)
Dumbledore tells young Tom Riddle that he’s been using his magic “in a way that is neither taught nor tolerated at our school” (273). What he doesn’t tell him is that an adult using one of these curses on a fellow human will almost always receive a life sentence in Azkaban for it. Curses like the Imperius and Cruciatus should be well beyond the abilities of a child just starting at Hogwarts, but Tom already seems to have learned how to make them happen on command.
“‘Tell the truth!’ He spoke the last three words with a ringing force that was almost shocking. It was a command, and it sounded as though he had given it many times before. His eyes widened and he was glaring at Dumbledore, who made no response except to continue smiling pleasantly” (Half-Blood Prince 269-70)
Only a skilled occlumens can lie to the adult Voldemort, and eleven-year-old Tom Riddle already seems accustomed to being able to demand the truth. It seems like he’s learned to tell whether others are lying to him, although reading Dumbledore’s mind is more difficult. Alternatively, he could be trying to use the Imperius curse, which would force Dumbledore to tell the truth in a different way.
Perhaps what Dumbledore tells Tom Riddle is the answer: “At Hogwarts … we teach you not only to use magic, but to control it” (273). Young children’s magic in the Harry Potter series is spontaneous and uncontrollable. It’s not the power they lack at such a young age, but the ability to use it in any kind of consistent way. Much like any real-world talent, the raw ability won’t amount to anything unless it’s studied and refined.