You are talking about autism. Autism is very commonly described as a disease or disorder, disability, etc. How do you compare it to "being most aware", and especially in the context of the term "sane"? It seems that the two are very differnet things that have little to do with each other. "Constant awareness" as you described it is surely not the kind of awareness that they meant when talking about "sanity"? Any regular normal healthy person, if they were being "constantly aware" of everything they already know and can perceive, even though that set of things is much smaller than the set of things available to a highly functioning autist, would already be too much to be able to function. In such a case it is then more of a disorder in focusing, not the question of how less or more aware you are?