Autism runs right through my ex-husbands family. Of course, back when he was a child, no such term existed. First really diagnosed case was my eldest g.son - after battles with educational services his parents did manage to get him to a special school for a few years, where he learned good management techniques. Very much in his control now as he is succssfully going through Uni on a high level science degree.
Interestingly, back in 1971 I used the term autism with regard to the behavior of my eldest child ( a boy) who was then a pre-school age. This was totally dismissed by the social worker who was fascinated that, at the age of four years, he was reading and understanding, quite advanced books. The fact of his incredible tantrums and habit of going to find a hard surface on which to bang his forehead until it bruised was dismissed.
No diagnosis, we just coped. He detested any social occasions, got a scholarship to a good private secondary school, where small classes, etc helped him. Just about survived Uni and got a good job and career and a lovely wife..
His next sibling down who works in Mental Health always dismissed that I said he was undiagnosed autistic, until his 40th birthday,. Family had a nice meal out in restaurant. Fine, until the waiters came out with cake all singing Happy Birthday - at which point he got up and left the restaurant!!!
He is now turned 50 years of age - loves being able now to work entirely from his own home - something he has been asking to do for some years.
He is highly skilled in IT and holds down a good job, has a lovely wife, and a beautiful house. He has friends, but virtually all of them are on-line . I can remember a few years back asking my DiL if he ever socialised with any of his fellow work team members, and she just laughed at that. Of course he did not!!!
He has a good life, all the family know he is well on the Autistic Spectrum. Does it matter, NO......Does he need a diagnosis - absiolutely not.