Today marks the 18th anniversary of the introduction to some of our favorite '90s cartoon characters: everyone's favorite football head, Arnold, and the world’s hardest fronter, Helga. As we sat in front of our television sets binge-watching Nickelodeon we never realized just all the gems the creators of Hey Arnold dropped for us. Instead of a cookie-cutter storyline, creator Craig Bartlett introduced us to a diverse cast with a colorful palette of children. Race and religion was a non-factor for the kids of P.S. 118. Here are 7 things Hey Arnold taught us about diversity.