Readings of Feast: http://usccb.org/bible/readings/020216.cfm
The Gospel narrative clearly becomes a moment of proclamation, another announcement of the destiny of this mysterious child. What is somewhat surprising is that Mary and Joseph were, "amazed at what was said about him (Jesus)." It is not the first time that they seemed to be kept in the dark somewhat by all the implications of Jesus' birth. Gradually, over time, they come to understand the destiny of this child, which is the normal way that we all learn.
If God were to reveal himself in his fullness to us in one instant it would be too much to bear. We learn over time, we grow, we reflect, we experience, we listen, we are moved to a response as a normal way of learning and when we leave this life, we do so still in ignorance of God's fullness this side of Heaven. No doubt both Mary and Joseph came to understand as their normal, but not so "normal" child, "grew and became strong, filled with wisdom; and the favor of God was upon him." (Lk 2: 40). All this in the hidden life of Nazareth.
It begs the question as to our own process of growth in the faith. How have I come to believe? Who first introduced me to the faith and where am I at today with it all?
Almighty ever-living God,
we humbly implore your majesty
that, just as your Only Begotten Son
was presented on this day in the Temple
in the substance of our flesh,
so, by your grace,
we may be presented to you with minds made pure.
(Collect of Mass)