littlebabyjesus
one of Maxwell's demons
The reason why a question cannot be answered is very often to be found within the question. If it is a badly formed question, it may be that cannot have an answer. Coherence is surely a necessary condition for a valid question.Questions don't have to be coherent to be valid.
In this instance, I would argue that treating the question as if it were coherent creates the mystery. Properly considered, isn't the answer that there is no mystery - there are certain things that we cannot say, and we can have a good idea both that and why we cannot say them.
At heart, this is a logic problem. Godel's incompleteness/Turing's stopping problem. Seen from inside, there is always necessarily going to be something about the system that we cannot prove to be true from within the system but that is nonetheless true - has to be true, even. That seemingly contradictory position whereby we can know something to be true without being able to prove it.