It is sometimes an appropriate response to reality to go insane.

Fat realized that one of two possibilities existed and only two; either Dr. Stone was totally insane – not just insane but totally so – or else in an artful, professional fashion he had gotten Fat to talk; he had drawn Fat out and now knew that Fat was totally insane.

Perhaps if you know you are insane then you are not insane. Or you are becoming sane, finally.

Matter is plastic in the face of Mind.