Other than the simple fact that Jesus lived in Nazareth with His parents, the only Biblical record of His life as a youth is a description of one of the family’s annual journeys to Jerusalem for one of the annual Passover Festivals.
On the family trip to Jerusalem for the Passover Festival, in Jesus’ twelfth year, Jesus became separated from the family group heading home to Nazareth. He had remained in the Temple to continue a discourse on the Scriptures with the rabbis.
Jesus stayed behind for a tutorial with the Temple rabbis and teachers, who were amazed by the boy’s level of understanding. At twelve years of age, a Jewish boy could start his training to become a rabbi, which would be completed at around the age of thirty if he was sufficient academically to finish. By twelve a boy who wanted to become a rabbi needed to quote the Torah, the first five books of the Bible, from memory.
After Jesus’ parents had found Him, they continued their journey home together. The Bible, at this point in Jesus’ life, does not say much more about Him, until He commenced His public ministry. The Bible clearly says that Jesus had a number of half-brothers (including James and Jude) and half-sisters, because Joseph and Mary had more children following the birth of Jesus. Mark 6:3.