^I came across the term about 2 decades ago.At the time the only official dx I had was schizoaffective mixed type. I suspected there was more than just the schizoaffective , but my then mental health tram put everything down to the mental illness.
I had learnt to read by the age of 3.5 or so, and was looking at children's encyclopaedias before I went to school.
However was not the archetypal gifted child/teenager. The 8 year old who was in a class for those who were 12, for example. My prep school headmaster described me as 'not particularly intelligent'. I was more a B- type than an A+ type.
A few years ago my father told me this.

That was pre teen. Some time between 1965-1968. Tests created by a psychometrician over the last couple of years give a very similar result.
Whatever potential I had was destroyed years ago. Firstly by severe verbal bullying, and then by years of pdocs, and other mental health pros, thinking that constantly criticising me was a good proxy for help and support.
My current mental health team I can't find fault with at all. However they can't reverse the damage of the past. It's not always easy accepting how things are compared to how they could/should have been.
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Socially drifted middle class