What piece of art or pop culture first got you thinking critically?

I always enjoy reading and participating the AV Club’s Friday Q&As.  (I’m not going to tell you my username there, but I will tell you that, to quote The Simpsons, it’s “a name that’s witty at first, but that seems less funny each time you hear it.”)  They usually ask the staff about which work of art or piece of pop culture caused a particular reaction in someone or made them consider something for the first time.  A couple of weeks ago, for example, the question was on which work of art made them reconsider religion (or consider it in a context outside the one they were raised) for the first time, which led to some nice examples and discussion from both writers and commenters (on another note, the AV Club’s commenters are among the most thoughtful bunch I’ve found on the Internet).