Something happened and now I can't talk about it because of the nature of what was revealed to me. Typical. While you know nothing, you can speculate all you want, but once knowing, it's impossible to talk about it because your knowledge of specifics would make you unknowingly address things in ways which can lead to the truth of the matter being derived from what looked like general statements. This would in turn put things at risk, because certain knowledge will be abused by opposing or degenerative forces.

It seems esoteric knowledge needs to remain such, for the same reason you can't walk nude in town, or taunt wild animals unarmed and survive. It doesn't matter how much you reason about it, some people will be upset, others will be hostile, they will use their own limited and flawed views to attack things that must not be attacked, in the process maybe rendering themselves unsalvageable because of what they in their ignorance did. This logic is so clear once this knowledge is revealed, that a mental block of some sort will prevent the person from speaking about it. Not even an insane person could break it, unless he was genuinely insane and recognized as insane, at which point he would be unable to speak the truth because of being too confused.

The Dao which can be spoken is not the real Dao, indeed.