For me, it merely brings it to the level of "interesting speculation". What observations would provide strong evidence that there be dragons? Other weak evidence that just leaves it at much the original level is the existence of anosognosia -- people with brain damage who appear to be unable to think certain thoughts about their affliction. But that doesn't prove anything about the healthy brain, any more than blindness proves the existence of invisible light.

Some people seem unable to grok mathematics, but then, some people do. The question is whether, Turing-completeness aside, the best current human thinking is understanding-complete, subject only to resource limitation.