But Mary asked few questions ("How can this be since I am a virgin?" is the only recorded question) and simply says, "I am the Lord's servant; may all be as you have said." And that is the hinge of all history: Mary agreed to be the vessel through which God would come come in the flesh to save all humanity.
As we are in the final week of Advent, let us take time to reflect on our willingness to say "yes" to God. It's easy to say "yes," but we must be willing to let our lives be upset because of that. Mary's plans were set aside, her hopes and dreams changed. That's what following God is about: being willing to let His plans be ours--and letting our plans simply be to be available. But when we are willing, the whole world can be changed because of it.