You are confusing the "the internet" with "the web".
The internet has been around for about as long as it's been sensible to describe an online culture. While in the early days (e.g. 70's, 80's) the internet certainly wasn't the only network to be influencing culture (c.f. FidoNet) it was a primary source, particularly via university campuses.
Exactly - the internet had been a big contributor to online culture through the 70s. Of course this stuff all had precursors in things like ham radio, model trains, etc. but it's not really sensible to identify those as "online". Nothing springs from the void.
Nice to get called "young man" though, it's been a while :)