Why is “thirteen year old gamer” one of the geekiest groups… 90% of the 13 year old population is on par with “trekkies who get married in Klingon garb?”

I was a gamer, but most 13 year old boys I knew weren't. In fact, once when a couple of my friends from my basketball team were over at my place they absolutely marveled at the cup full of various sided dice in my basement. They asked, "What's a dice with twenty sides for?"

Oh, and I'd have to say that the gamers I knew pretty much were on par with "trekkies who get married in Klingon garb". And so was I.

Ka'Plah!

Perhaps it's about the "consider themselves [...]" part? And who says the chart is transitive?