LK When his parents saw him they were astonished and then his mother said to him: “Son, why did you do this to us?
 Look, your father and I were in a lot of pain searching for you!
” LK Then Jesus said to his parents: “Did you not realize that I would be in my Father’s House?
LK Then he descended with them and they all arrived in Nazareth and there Jesus continued to be in subjection to his parents.
His mother treasured all of these things in her heart. LK And Jesus continued to increase in wisdom and physical growth and in favor with God and people.  Jesus was listening to the teachers and asking them questions: Nothing here tells us Jesus was teaching these rabbis. At the age of twelve the Jewish boy became a “Son of the Covenant.” The next phrase shows Jesus answered their questions well and this impressed those listening. It is interesting that such an intelligent lad did not make some provision for telling his parents.
 Son, why did you do this to us: Or, Child; TCN: treated us like this. Perhaps he knew had he asked they would not have given their permission. The Greek is only “things” and so does not refer at all to the Jewish temple proper.
There were several courtyards in the compound of Herod’s temple.
A woman was not permitted in the Court of Israel where only men worshipped God. The word “house” is used of the tabernacle of Moses and the temples that followed.
[Psalm 26:8; 27:4]  Did not understand: This was a common reaction to things Jesus said, including his own later disciples.
To Bible readers looking at matters in retrospect the failure to understand is surprising.
The use of the word “Father” was very rare in the context of God.
LK Now each year [Jesus’] parents traveled to Jerusalem for the Passover festival.
LK So when Jesus was twelve years old he went up with them according to the custom of the festival.
LK After fulfilling the days [of the festival] [the parents] returned but the boy Jesus remained in Jerusalem.