Each year his parents went to Jerusalem for the feast of Passover, and when he was twelve years old, they went up according to festival custom. After they had completed its days, as they were returning, the boy Jesus remained behind in Jerusalem, but his parents did not know it…
his mother said to him, "Son, why have you done this to us? Your father and I have been looking for you with great anxiety." And he said to them, "Why were you looking for me? Did you not know that I must be in my Father's house?" But they did not understand what he said to them. He went down with them and came to Nazareth, and was obedient to them; and his mother kept all these things in her heart. (Lk 2:41-51)
The quality of the immaculate heart of Mary is to search for the lost son. The search did not count the cost. Mary was ready to travel back the whole distance. The search is also personal: she goes searching. The anxiety of the mother is expressed in the question she addressed to her son. Hear of the mother longs to be with the son and if the son is lost then searches for the son until he is found.
She kept all the happenings in her heart and reflected upon them. Mary knew well that Jesus was different from the rest. And whatever happened to him were also different. Right from the arrival of the angel Gabriel, all the happenings were of different nature. Mary could only meditate upon them.
The feast of the immaculate heart of Mary presents to us the qualities that we could also cultivate. Immaculate heart is one that searches for Jesus and goes after Jesus. A heart that keeps everything and reflects over it.