We read in Luke 2 that: "… when he was twelve years old, they went up to Jerusalem… And it came to pass, that after three days they found him in the temple, sitting in the midst of the doctors, both hearing them, and asking them questions. And all that heard him were astonished at his understanding and answers…. And he said unto them, how is it that ye sought me? Wist ye not that I must be about my Father's business?" So, we find that at age 12, Jesus was well aware of his earthly mission and of his purpose and understood exactly who his Father was, yet we are led to believe by many Biblical authorities that Jesus from the ages of 13 through 30, spent his time and his activities as a carpenter with his earthly father. While it is certainly possible that Jesus did so, with the exception of some scriptural passages that imply that the population knew him as a carpenter's son and as a Nazarene, this general belief by the public could just as well have come from the fact that as a child, Jesus grew up in Nazarene and that his earthly father was a carpenter.
When it comes to the missing years of Jesus life, one must ask yourself the basic question, as to how do people become great lawyers, or great doctors, or great composers, and the only logical answer is that they become so by hours and hours and years of learning, listening, applying, and much dedicated practice and work. It isn't possible to become a great master of anything without sitting at the feet of those that have accomplished these things themselves, and testing your knowledge and your skills against those that have the insight to help guide you and to correct you. For those that accept Jesus as the Christ, as the Son of the living God, how is it even conceivable to believe that the Christ would waste away his time as a mere carpenter for eighteen long years? I suppose the answer could be that God works in mysterious ways or to show the humility of the Christ, but neither of these is satisfactory, whatsoever.
In point of fact, to become the Christ, to become the savior, is not only an act of obedience and surrender to God, but also necessitates the mastering of this particular skill-set to the highest possible degree so as to later conduct his Father's business without error or fault. This type of divine expertise must be nurtured and developed over a considerable period of time, as they that believe that one is simply born into greatness are hopelessly misguided, as greatness is something achieved only through perseverance, consistency, application, and guidance.
While we may not know physically where Jesus was from the ages of 13 through 30, we do know for a certainty that during those years, he was activity pursuing his Father's business so as to master his trade and to become both the son of Man as well as being the son of God. One would do well to acknowledge that the earthly plane is not the same as the heavenly plane, and that the earthly brain is not the same as the omnipotent and omniscience God of the universe, the God of all creation, the Alpha and the Omega. In actuality, to be the Christ, necessitates the disciplining of the physical body, as well as the emptying from the mind of one's ego, with the replacement of this with divine wisdom. This is the only way that Jesus the Christ could become God manifest.