The time of Jesus that is lost, or not recorded in the Bible, was His time of growth, His time of Self /God realization. To the world He seemed not one to take much notice of, for He was not a physical manifester. He was not intent on being caught up in the world. His focus, His desire was finding and manifesting Me perfectly. Thus so, He was lost to the world.
Excerpted from the book Listen Hear, A Divine Love Story by Debra Clemente