He wasn't very good at Math back then, so his parents sent him to a Kumon Math Center. It traumatized him. He couldn't grasp the use of memorization or math tricks by then, so he couldn't finish work sheets fast enough. They had him keep on repeating, and all he could do is to mentally count fast enough to trick his teachers into thinking he could add and subtract. By multiplication and division, he had to count faster. When he finally grasped basic math operations, he was able to solve each operation at the same rate as his counting speed; solving complex math equations near-instantly. At this point, the Kumon Center kept feeding him more math far above his grade level. By the time he was finally released, all he could see were numbers swirling around his head. Since then, he'd always see numbers in front of him, calculating everything he could see, hear, and even feel.