Luke 2.51-52: And he went down with them and came to Nazareth and was submissive to them. And his mother treasured up all these things in her heart. (52) And Jesus increased in wisdom and in stature and in favor with God and man. (ESV)
When Jesus had finished his time in the Temple with the scholars he returned home to Nazareth. So in the normal course of pursuing God’s will for his life, Jesus at the age of twelve showed an extraordinary measure of insight into the things of God. This is more than being a prodigy. The world has seen many prodigies at various times and ways. This interchange in the Temple was of heavenly inspiration and origin. And yet with all of this being said, Jesus returned home and submitted to the authority of his parents.
And even though Jesus demonstrated knowledge beyond his age, he still had eighteen more years of development to experience to bring him to the point for his public ministry to begin. And these additional years of development were appointed, even for Jesus. This growth God worked in Jesus was not necessarily observed by his family, relatives, and neighbors. Mary certainly could see them because she treasured these things in her heart. But as Luke tells us in chapter four, many of these same people were unbelieving or skeptical that Jesus was who he said he was and is.
So God worked these extraordinary attributes and capabilities in the life of Jesus, while at the same time Jesus had the appearance of being ordinary to those around him who were not looking at him with discernment.