Imagine yourself holding Mary's infant. Look at his tiny hands, his mouth, his sleeping face.
For some reason, when I usually imagine the scene at Bethlehem, the baby Jesus is not a newborn, but a child of several months. Perhaps it's the effect of all those nativity scenes where the statue of the infant is holding out his arms and smiling.
Newborns don't do that. Newborns are tiny and helpless, totally dependent upon others to care for them. It staggers the mind to think that God the Son, in becoming incarnate, made himself totally helpless and dependent upon Mary and Joseph. Perhaps that is why he was born in such humble and inconspicuous circumstances, with the glorious news announced not to the learned or to the masses, but to the shepherds in the fields with their flocks.
Of course, Mary and Joseph did care for the child. Joseph might have needed a little prompting from the angels to take Mary as his wife and to lead the Holy Family into exile in Egypt. But upon receiving the messages from the angels, he promptly acted in faith upon what had been revealed to him.
On this Feast of the Holy Family, let us all emulate Mary and Joseph in responding to God's revelation. Mary and Joseph, pray for us. Lord Jesus Christ, have mercy on us.