First, do the math. By my calculation, Jesus passed over 500 Sabbaths from the day he saw Nazareth until his Passover visit at age twelve (in March of 7 AD, some months after Archelaus was exiled). Ten years of Sabbaths is enough time for a very small child to grow into a very impressive twelve year old, IF that child paid very close attention because of a deeply held passion for any and every thing that was of God. (Hold that thought briefly.)
What we see in the Lord's age twelve episode is an impressive degree of focus - we might even say fixation - on the "business" of God. As that business seemed to include listening and asking Rabbinical questions about God's Laws, we should expect that twelve year old was very much interested in the ways of the Synagogue. In fact, it becomes plainer and plainer that the only shockingly inconsistent fact here is that he kept all that insight to himself when he went back to Nazareth. (Hold that thought too, for a bit longer.)
The age twelve episode also reveals some awareness of a unique personal Sonship to God as his Father. It doesn't matter how we define this. A young Jewish boy considered God his personal Father in some unique way. That should be enough to convince us that this kid was passionately wrapped up in this whole God thing. His entire self-definition, sense of purpose, direction and identity, was completely summed up by one simple reference to his Father. (It was never about the "business". It was always about the Father.)
It is that focus, that healthy obsession - *(and it was healthy, because it was balanced, because he was able to obey his parents and leave Jerusalem immediately - which we should see as one more gracious provision of God for his Son, during his development)* - that genuine and utter worship of his Father that possessed and inspired Jesus to pay close attention each Sabbath day in the Nazareth Synagogue, focusing on each reading of Law and Prophets acutely in terms of what it had to do with the Father, above anything else. Furthermore, Jesus must have maintained this practice in earnest for many years before he became proficient in communing spiritually, mystically, with the One he already adored.
In that process of worshiping God, Jesus also learned scripture. But how did he learn the scriptures so well, just from Saturday meetings? At the risk of repeating a key point once too often - Jesus must have been paying attention.
To be continued...
Series Update: The Nazareth Synagogue