This episode aired the same day that Looney Tunes had its final run on Nickelodeon.
The graffiti Grandpa Phil was writing was Steely Phil. This was a reference of an episode of Steely Phil.
Adults whom return to school do not go to regular elementary schools, they go to specialized adult schools.
Aren't the students suppose to respect Grandpa Phil since he is 81 years old and an elder? And if Grandpa Phil is so old and much mature than the other kids, then how come he gets scared of the mean-like kids when he enters 6th grade for the first time? Grandpa Phil is an adult, the kids can't bully an adult. And Grandpa Phil is also shown going to the theater with Connie and Maria from school as if they were his girlfriends. Grandpa Phil is way too old for Connie and Maria.