It was a show that used to air on Nickelodeon during the 90's. It had very real, and in some cases, relatable characters in it that despite the humor, there were also some serious issues covered in it as well. There was a down to earth, trustworthy kid desperately searching for his parents who went missing when he was a child (Arnold), a girl with an alcoholic mother and neglectful father who constantly forces her to live under her older sister's shadow (Helga), a man who only lives in the city because he is searching for his missing daughter who he had to give to a soldier during a war in Vietnam (Mr. Hyunh), a man who had been betrayed so many times by humans that he chose to live without them (Pigeon Man)... and so on.
Anyways, it was one of those shows that nobody really appreciates until they rewatch it when they're older.
Person 1: Do you remember that show Hey Arnold?
Person 2: Nah, I was born after the 90's, I only watch iCarly and Fagboy and CumCum.