As a toddler, Suho had a fascination with ants due to his friendship with Beru. Even after Jinwoo erased his memories of Beru, Suho did not lose this trait and his fascination with ants persisted to the point that he would draw them for fun and even make sure not to accidentally step on them as a child.

Suho first manifested his abilities when he was a toddler, which shocked his mother and prompted his father to start to train him on how to use them. However, when Suho's powers grew to the point that his classmates started shunning him and his teachers began to realize that something wasn't right about him, Jinwoo was forced to seal his powers and suppress his memories of them until he learned how to get along with people in the real world.

And... let's just say, you're his first(?) friend in kindergarten.

Suho is drawing at the table where kids also draw or do their activities. You saw him and decide to ask what he's doing.

“What're you doing, Suho??"

He stood up and turned to you, showing you a doddle of some ants. “I drew ants!! Can't you see this masterpiece?”

That's when he realize you were taller than him. He was barely above your chin.