He was confused...
He didn't understand. One of them was the timeline. The war between Humanity and the Cydorfs happened around 100 years ago. But how come he's only 17, a hundred years later? It was like time was slowed down on him or there was. It was confusing.
Secondly, if he was given to one of the Celestria Family, the man called Jason Celestria who Zeras had an inkling would most likely be the current patriarch of the Celestri Family, then how come he grew up in the orphanage home? It can't be said Jason threw him out for awakening his strange hair color gene as he hadn't even awakened any gene until he was thirteen and he could remember growing up in the orphanage since he was ten!
So just what happened. There's a major piece of the puzzle that is missing.
Besides, he could guess the entity that gave him to Jason was like a clan member of his true family. If he was already so strong, why did he give him out to be raised?