Jesus at age 12 remained in Jerusalem after His parents had departed from the Passover feast.  They returned to find Him three days later.  They found Him in the Temple engaged in His Father’s business.  We still find Him in the place of worship; we still find Him when we also engage in the Father’s business.  The Galilean pilgrims may have been taken up with the festivities of the occasion.  Jesus was to what the occasion pointed.  Later on, after another Passover, by His own resurrection on the third day, He would become the Temple, our meeting place with God.  

46 After three days they found him in the temple, sitting among the teachers, listening to them and asking them questions. 47 And all who heard him were amazed at his understanding and his answers. 48 And when his parents saw him, they were astonished. And his mother said to him, “Son, why have you treated us so? Behold, your father and I have been searching for you in great distress.” 49 And he said to them, “Why were you looking for me? Did you not know that I must be in my Father’s house?” 50 And they did not understand the saying that he spoke to them. Luke 2:46–50 (ESV)