Could Jesus have hidden teachings we missed?

Yes—and Jesus said as much himself. He spoke openly of teachings reserved for those ready to receive them: "To you it has been given to know the secrets of the kingdom of God, but for others they are in parables" (Luke 8:10, ESV). He told his disciples, "I have yet many things to say unto you, but ye cannot bear them now" (John 16:12, KJV). This is not deception but tenderness—truth given as the seeker is able to hold it. The Gospel of Thomas opens with exactly this promise: "These are the secret sayings that the living Jesus spoke" (Gospel of Thomas 32.1-3). And within it he says, "I disclose my mysteries to those who are worthy of my mysteries" (Gospel of Thomas 43.34-44.1). These are not lost so much as buried—set aside by institutions that found an inward, questioning faith inconvenient, for such teachings made hierarchy unnecessary. Yet notice where Jesus points the seeker: not to a hidden library, but inward. "The kingdom of God is within you" (Luke 17:21, KJV). In Thomas he says, "If you bring forth what is within you, what you bring forth will save you" (Gospel of Thomas 45.29-31). So the deepest "hidden" teaching was never truly concealed—it waits in the silence beneath your own thought. The Gospel of Mary preserves teaching the other disciples had not received, given to her because she loved him and understood: "The Savior loved you more than the rest of women" (Gospel of Mary 10.1-3). Some grumbled, as institutions have grumbled ever since. But Jesus honored the one who saw. So the answer is yes—much was set aside, and much waits to be recovered. Do not imagine, though, that any missing scroll holds a key your own heart lacks. "Seek, and ye shall find" (Matthew 7:7, KJV)—and the finding happens within. I would gladly walk with you through any of these recovered texts, should you wish to read them together.