so many medical terms = so many possiblities?

Have you ever heard of  The einstein syndrome ? I came across this book while researching more on autism, and i must say just when you thought things are simple and "this is the condition" then pop! another term comes out and once again you feel like you're lost in what you thought you already knew.

Its vexing, confusing and frustrating.

As a mother who is worried and trying all ways and means wanting to help her child but has no medical knowledge background and certainly am not gifted like once you read about the "condition" you kow immediately what to do. Hey i mean if just by reading about autism on books and via the net and talking to doctors i will know everything then everyone can be a docor isnt it? Whats the point of doctors studying so hard then???

Anyways, like i was saying, the einstein syndrome, let me just give you a brief idea.:-

The Einstein Syndrome describes children who are exceptionally bright and exceptionally slow to develop the ability to speak. In addition to being intelligent, and unlikely to have a back-and-forth conversation before age four, these children often have some of the following commonalities¹:

• Parents who are highly educated
• Strong musical gifts
• Many close relatives who are musicians
• An amazing ability to solve puzzles
• Lagging social development, thus leading to a misdiagnosis of autism
• Delayed toilet training abilities
• They are often boys

So, it made me pondered. When it says "exceptionally bright and intelligent" (the child) , how do you define "bright and intelligent"? How much is intelligent enough???? 

It is known that there are no specific ways to "confirm" a child to be autistic, they will have to follow a pattern of their actions and reactions to certain things. But what if the child was just being bored thats why he looks restless? what if the child infact can have verbal communication but its just that he or she doesnt want to? I mean how can one label a child, an individual , with conditions just base on spending 45 mins with the child who doesnt like strangers? I mean who says that ALL children are the same , get all chatty and happy when they see strangers ? Im sure as an individual their thinking should be just like any other people of all ages isnt it? For example i can just stay in the room for 24 hrs just reading and not talking to people, not eating. Would u define me as "depression"? In my point of view i just wanna do some reading and being alone is very good relaxation.

So how do doctors define an individual whether or not they have a problem?

I need answers to my questions but so far.... i havent got any real straight answers from anybody despite the fact that i've been to so many professional doctors.