It has been recorded in the Gospels that young Jesus stayed behind in Jerusalem after the Passover Feast. His parents found Him after three days in the temple, hearing and asking questions in the midst of the wise men. People were amazed at his knowledge and the answers He gave at the young age of twelve. When his parents found Him, He said to them,
How is it that you sought me? Do you not know that I must be about my Father's business? Why were you looking for me? Luke 2:49
According to Jewish customs, boys at the age of twelve should start working with their fathers and to learn their trade. Even though Jesus was brought up by Joseph and Mary, His Father is God. Therefore, Jesus at the age of twelve started doing His Father's work in His Father's house (the temple), hearing and answering questions among the people there.