That classic '90's Nickelodeon cartoon, Hey Arnold. The height of childhood innocence, a story of a boy and a group of his school friends, it delves into the world of playground bullies and name-calling, schoolgirl crushes, but usually nothing more serious than that. Or so it seemed at first viewing. If you re-watch it as an adult now, however, you'll be shocked to learn some of the hidden gems within the show. At this point we give a shout out to none other than Hitler for the cameo in the show. No, we're deadly serious: As a kid, you probably watched the show and didn't have a clue who this was portraying, at least not to the extent you do now. Throughout are some more innuendos, references and hidden images from a cartoon masterpiece of our childhood that might just make you look back differently upon your early years... or you know, you might just chuckle at them like I did. Click "next" below to begin...