On the other hand, when I was first introduced to Linux ~20 years ago, I didn't have an "always-on" Internet connection and web sites weren't that popular.
Probably 90% of what I learned in the first few years or so came from the man pages and a locally downloaded copy of the guides and howto's from TLDP [0].
I might also mention that not all man pages are created equal. I've seen some in Ubuntu that serve no purpose other than wasting bytes on the disk while some of those in OpenBSD act as a single source for everything one needs to know about <tool>.
[0]: http://www.tldp.org/