Suha*
But he does remember him, it's just that Suha could never treat the director like an equal because he was always superior to him in spite of being younger, as he was son/grandkid of the family that Suha's mom or dad worked for. Even if the director called Suha 'hyung' and he and his mother and sister were treated as guests by the family they worked for, that family were still 'the boss'.
Maybe suha lost his memory?
He didn't. He just never had a super close relationship with kid Director Park, just took care of him out of gratitude and obligation to Park's grandma, but didn't pay that much attention to Park due to their the age difference, their status difference, and the fact that Suha was too absorbed by his feelings for Park's older cousin/brother at the time.
Can someone tell me HOW Such doesn't remember the director? Why are those memories one sided? It's so unfair for the director ˚‧º·(˚ ˃⌓˂ )‧º·˚