To realize/tell somebody how stereotypical you/they are.
Originates from the first verse of the song "admit it"-say anything, which has lyrics that make fun of every stereotype you could think of.
LYRICS:
Admit it!
Despite your pseudo-bohemian appearance
And vaguely leftist doctrine of beliefs
You know nothing about art or sex
That you couldn’t read in any trendy New York underground fashion magazine
Prototypical non-conformist
You are a vacuous soldier of
the thrift store Gestapo
You adhere to a set of standards and tastes
That appear to be determined by an unseen panel of hipster judges (bullshit)
Giving a thumbs up or thumbs down to incoming and outgoing trends and
styles of music and art
Go analog baby, you’re so post-modern
You’re diving face forward into a antiquated past
It’s disgusting, it's offensive, don’t stick your nose up at me.