I'm not saying "right" or "wrong". But it occurs to me that humans are social animals. "It is not good for the man to be alone." Every child is 'formed' by his parents, even if the formation is nothing better than challenges that the maturing adult must overcome.
So, and this is just a speculation, IF we assert that Jesus was truly human, AD IF we assert that humans are in some respect "formed" by their parents and home, THEN it seems the characters and graces of Mary and Joseph would have to be influential in the development of Him who was truly God AND truly man.
Actually I don't believe it is speculation, rather, it is fact.
Luke 2:
51 And he went down with them and came to Nazareth, and was obedient to them; and his mother kept all these things in her heart.
52 And Jesus increased in wisdom and in stature, and in favor with God and man.