Ah. They showed him in a wheelchair, so maybe he asked for athleticism. He did have a scar, and his dad(?) did say he was "defective".
My guess is he had a car accident that crippled his legs and left a permanent small scar on his face. Maybe something to do with his mom, too, since we haven't seen her at all? Zhou Mo handed him that painting with that sunflower, and he saw it and it reminded him of the outside. He wanted to go outside, but was chained to his home because his rich family didn't want a "defective" son wandering around. He wished for that physical freedom, then, but sacrificed his memories of her.