Total obedience requires sacrifice, and produces infinite joy.
When Angel Gabriel came down to visit the Blessed Virgin Mary, she, who had been prepared for this moment her whole life, said, simply “Yes. I will.” Just what did she agree to? She agreed to be overshadowed by the Holy Spirit, and conceived a son out of wedlock. She agreed to be in danger of stoning and disgrace at the hands of her husband, Joseph. She agreed to the prophecy of Simeon, that a sword would pierce her heart. She agreed to flee into Egypt to keep him safe. She experienced loss when he was gone for three days in the temple. She agreed to watch him suffer at the hands of the Jews and Romans, to watch him suffer on the Cross when she was given to the beloved disciple (in fact, all of us). She agreed to hold him as he was taken down from the cross, and buried.
But in the midst of her life of sorrow, she also experienced great joys. The Annunciation, itself, was a great joy, as was His birth. The adoration of the Magi must have brought great joy, for here he was proclaimed to be the Messiah. Then after the utter heartache and sorrow of the passion and death of our Lord, came his glorious resurrection, ascension into heaven, and finally, her placement as Queen.
Today we thank our Mother for her sacrifice, for giving her life to the Lord.