One can find much interesting reading about Yeshua's early years in texts not included in the KJV.
One source I recommend is: The Encyclopedia of Lost and Rejected Scriptures: The Pseudepigrapha and Apocrypha Kindle Edition by Joseph Lumpkin
Specifically,
Introduction: The Life and Times of Jesus
Infancy Gospel of James, OR PROTEVANGELIUM
The Infancy Gospel of Thomas, Latin Text
The History of Joseph the Carpenter
I won’t hold to the veracity of such texts, but the small portion in the NT about Jesus in the Temple at age twelve does say quite a bit.
He was already into figurative speech, so it threw off his parents.
In the Temple, he was like ‘a kid in the candy store.’ D’oh. :)