Now there was a man in Jerusalem called Simeon, who was righteous and devout…then Simeon blessed them and said to Mary his mother, "This child is destined to cause the falling and rising of many in Israel, and to be a sign that will be spoken against so that the thoughts of many hearts will be revealed." Luke 2:25, 34-35
Simeon had waited all his life to say these things. The Lord had revealed to him that he would see the Lord's Messiah. He knew what was going to happen and spoke it over the boy and his parents. Again, we find a rather obscure man doing and saying something puzzling. I believe his proclamation benefited Mary and Joseph the greatest. Perhaps they just needed to be reaffirmed that what they had just gone through was a righteous act of God.
Having a gentleman approach you out of the blue to tell you your son would cause the falling and subsequent rising of Israel is enough for you to sit up and take notice, especially after you've had shepherd boys and Wise Men visit you. They needed to hear that message and Simeon needed to say it. And that's all we hear from Simeon.
I think one of the takeaways from these verses is simple: we really don't know how God is working in the hearts and minds of other people. We think we know but we really don't (we barely know how He's working in our own lives). And I believe that when more mature Believers reveal things to us that they could not know on their own, we probably should pay close attention.