The Buddha said, "Sometime, somewhere you take something to be the truth. If you cling to it so much, when the truth comes in person and knocks at your door, you will not open it." Guarding knowledge is not a good way to understand. Understanding means to throw away your knowledge. You have to be able to transcend your knowledge the way people climb a ladder. If you are on the fifth step of a ladder and think that you are very high, there is no hope for you to climb to the sixth. The technique is to release. The Buddhist way of understanding is always letting go of our views and knowledge in order to transcend. This is the most important teaching.