I agree. I was born in ‘61. I think there should be a ‘58-’64 (or perhaps ‘68) middle generation in there somewhere!
I’m 38, and have never been comfortable with the Gen X thing, though I guess I fit in some ways. I’ve always considered people born between about 1960 and 1972 to be some of a “middle generation.” I call it the Westerberg generation. Google it if you don’t get my tagline.