Hypnosis is a means that help to uncover the abundant inner resources inside each person.
For instance, under normal circumstance, a person may be very clear and confident that he can lift up a pen to write something. But when put under hypnosis, and being suggested that his hand is so wezk that he is not able to lift the pen, he fails to lift it.
What does this says? It reveals the person has much more resources and power within him that his conscious mind may not even know. He can deny all he wants, but the power within him is still as real as day and night. It may be dormant most of the time until certain technique/ event/ circumstances bring tap or trigger it to make it active.