The "Web" started with the server "nxoc01.cern.ch" which came online in November 1990. Of course, not many knew about it until the mid 90's, but still, it was around for most of the early 90's.
Yes, but I do not think that Online fabulism regarding rock climbing became in vogue until the late 90's or even the early double-naughts.
Before that, I would just lie directly to people to impress them. You know, craft individual lies for each situation?
Now it is harder because the lies need to get spread to more people and have to be better researched and thought out because too many people have too much access to too many resources.