the term air head is the current version of idiot, and means the same thin. those at the time that said that, since he could not do simple math, he had to be an idiot.
perhaps the common claims that he was too intelligent to understand simple math (as i understand it, he tried to understand it in more complicated math) is just more folklore, such as Edison not being able to tie his shoes. not being there, all i know is that this is one of the stories i have heard since i was in elementary math. perhaps only in certain areas of the world do they teach school children that many of the great leaders of many endeavors had flaws. or perhaps you believe that they did not have any flaws. many ppl of the time saw these flaws as indications of low intelligence. this was the case with Einstein. he did preserver and many are not now willing to accept that he had any flaws.
so in one way you are correct. they did not use the term air head with him. it had not yet been invented. but the term does mean that idiot.
as to the subject of the sentence, if the subject of an argument is known, its normally assumed by normally intelligent ppl that the sentences in the argument are about that subject. since you do appear to have a problem with keeping track of the subject, ill try to reduce my standards enough to suit you.
