The problem with Jesus' statement to us - 'He who has ears to hear, let him hear' - is that we are not always reliable judges on the matter. Most people think they have ears to hear, but I think that on our own - we tend to hear mostly what justifies us, reinforces what we already believe, and protects us.
The disciples did not understand the parables - and the truth is, we would not without help (Jesus helped us directly in some cases). Jesus said that part of why he taught in parables is to give a deeper truth to those who could hear it, but also to provide some concealment for those who were not going to hear anyway.
We need divine help to hear the divine message, any divine message - and if we don't think we need divine help, well, that probably is not a good sign.
