“Now his parents went to Jerusalem every year at the feast of the passover. And when he was twelve years old, they went up to Jerusalem after the custom of the feast. And when they had fulfilled the days, as they returned, the child Jesus tarried behind in Jerusalem; and Joseph and his mother knew not of it. But they, supposing him to have been in the company, went a day's journey; and they sought him among their kinsfolk and acquaintance. And when they found him not, they turned back again to Jerusalem, seeking him. And it came to pass, that after three days they found him in the temple, sitting in the midst of the doctors, both hearing them, and asking them questions.”
Luke 2:41-46 KJV
In this passage I see how easy it is to leave Jesus behind and not even realize it. Joseph had been gone a whole day before he even realized Jesus was no longer with them. If you notice that it took him a day to realize he was gone and 3 days to get back to Him. Leaving God behind doesn't take long but getting back in His presence can take awhile. Mary looked for Jesus in her friends and in her family and friends, I think this is a picture of how we look for fulfillment in other people but only He can fill our hearts the way they were created to be filled. Let me state too that Jesus never left Joseph, Joseph left Jesus.