Isn't everyone in grad school 27? (except for ones who are 26 or 28).
I beg to differ, and in fact I hope he's merely using hyperbole for the sake of hyperbole. Starting first with myself: although it is true that I started graduate level work (at Cal State Fullerton) at the age of 27, I spent the bulk of my grad school career as a thirty-something. In fact when I entered a Ph.D. program in Social Psychology at University of Missouri, I was one of the older students among the first-year crew (collapsing across all grad programs in psychology). Most of the people in that in-coming group were either in their very early 20s or were in their 30s to well in their 40s. Now if one wants to make a general observation, such as that most grad students are somewhere in the neighborhood of 27 years of age at any given time, I probably wouldn't argue with that too much. Just be aware that many of us start and complete graduate work somewhat (in my case) to considerably later in life.