English Standard Version (ESV)
Some things are for you and for you alone.
It must have been humbling for Paul -- here he was, surrounded by his fellow travelers, many of whom held him in high esteem as intelligent and passionate. He was seen as a leader, and suddenly he is on the ground, blinded by an unseen light and talking to an unseen voice. The voice of God speaks, but only Paul can hear it.
God speaks to us as individuals as well. Some things aren't meant for the whole world -- they are meant to quiet your soul, to assure your faith, to support your life. Jesus reaches out to us as individuals because that's how he loves us -- individually, passionately.
So just as Mary treasured the words of the angel, treasure the moments when God reaches out to you, but don't be afraid to reach for the hands of those around you as well. There are times we will be so overcome by what God has in store for us that we need the support of the community to move forward. They may not understand exactly what we are going through, but they can help us forward nonetheless.