There are probably infinite metrics by which to measure whether or not you are a true New Yorker. Were you born here? Do you have ready access to yellow (or green) taxis? Do you know not to ask for a toasted bagel at Murray's?
Whatever it is, you surely have an opinion. After all, we're not known as a particularly quiet group of folks.
One of those metrics happens to be your knowledge of local culture -- pop culture, in this case. Knowing your local celebrities is a sort of native literacy that can only be gleaned from years of riding the same trains, walking the same streets and, of course, frequenting the same coffee shops as everyone else on this horrifically tiny island (plus all of the outer boroughs).
So, let's see if you're a real New Yorker … at least according to those of us who measure time as the space between Billy Joel concerts.