Jesus spoke to people in parables because people weren't able to comprehend the things that he did, and in the way he did - including the mysteries of heaven. So nothing was "hidden" from anyone. That passage clearly states that the mysteries of heaven were revealed to Jesus, but not to the people that he was teaching (them).
Jesus also said, "I have so much more to teach you that you are not ready to learn" - paraphrased.
Again... I disagree with your interpretation of what is taught.