Annunciation - Advent 4

The Feast of the Annunciation falls on March 25 -- nine months before December 25. This coming Sunday, Advent 4, the Church invites us to look again at the Annunciation. The text is Luke 1:26-38. One question I am pondering is: what lesson(s) can I draw from the Blessed Virgin Mary saying yes to God's word as it came to her through Gabriel? Any thoughts?