Eh, maybe. While I am familiar with those things, I don't think I'd ever assume everyone my age and on the Internet would as well. Different strokes for different folks. Moreover, this didn't even take into account age at all. So not only did it appear to strike out with many of the same age, it'll likely strike out with most users who simply weren't on the Internet for that relatively small period of time.

Eh, my mom was on the internet at that time and would know absolutely zero of those things because she didn't visit humor sites. I knew them because that is the stuff I looked for.

Kind of like how most people watched MASH when it was the most popular show ever, but not everyone did.

Deeply offended at the lack of Homestar Runner in your list.

Epic rap battles and stumbleupon were my lemmy back then. Spent so much time stumbling and found some very weird stuff.

All I did on the Internet at that time was flash games and homework, later also "homework"