Just who IS Gen-X, Anyway?

Here's a "30-Something" who calls herself Gen-X and writes a blog all about nostalgia for the 80's. Now I'm "20-something" (still), and I never even heard of Roxy Music. For me, 80's nostalgia means Transformers and the kind of fashion that the chick in Napoleon Dynamite wears.



Of course I'm Happy to see you, waddya think? GOSH!

All of which begs the question: if generations are defined by shared cultural touchstones, and people who are born at different ends of generations have different remembrances, then how valid can the determination of a "generation" be?