Your phrasing of these two ideas don't correlate well.
A person is deemed "insane" by somebody who is deemed "sane." These are relative terms. If insanity is normal, is it sane? No. They are two different terms. However, insanity could be normal, and if the normal are believed to be sane, then the definitions of the two could flip-flop.
Nonetheless, one cannot be both sane and insane at once.
it's all relative. i guess it comes down to the question 'how well do i fit into the community?' a crazy person in a crazy town is not that strange. crazy person is actually now normal, cause they can function in the town. go about daily life and all that.
There are defining behaviors of insanity but it is generally relative. Now if you claimed the world was flat now I might be inclined to think you crazy but at one time that thought was the norm and was not so crazy considering the scientific understand at that time. Tis best to assume oneself is indeed insane and make effort to not be so or assume you do not know quite as much as you'd like to. Sanity to me, is the state of knowing all there is to know but given our limited data I have restricted this collection of data to an interval that is realistic based on a function of scientific progress to date and introspective studies of myself and others among other factors. I don't expect to achieve absolute sanity within my lifetime but I find the pursuit noble and of import as perhaps I can compose a portion of sanity and offer it to future generations.
If you're using the term insane in its medical sense, to mean people who are psychotic, then yes, there are standardized behaviors and thought disorders that justify that diagnosis. There are profound differences between people who are psychotic, and people who are not. It's true that many psychotics are unable to recognize that they are mentally ill, but sane people generally do know that they are sane.