"Young people know all about computers" was never true either. It was maybe true for people like you and me, the type of people who now frequent places like HN. But for the vast majority of people, computers were never all that interesting.

>"Young people know all about computers" was never true either.

That's true, but only because not all young people owned or used computers. I was born in the mid 70s and got my first computer as a young child. Back then you had to "know all about computers" to use the computer and get it to function. These days, every kid grows up surrounded by computers, with a computer in their pocket, and very few have even an inkling of how they work.

Thus "young people who use computers know all about computers" used to be a true statement, but no longer is.