The post apocalyptic setting really makes any simple kindnesses much more meaningful. Despite having met only recently, the survivors sit around the fire and talk like old friends. Once they realize that Gibson isn't dangerous, they welcome him in as well and even offer him one of their (probably limited supply of) beers.
After the disappointment over Casey Martin, a distraught Jenny asks Gibson whether she's used up her ten names yet. It turns out that she hasn't, but Gibson's automatic response of "I can do more," implies that he would have continued to help her even if she had.
The sheer glee with which the survivors respond to Gibson's impromptu theatrical performances. Not only do they love his Simpsons rendition, they enthusiastically cheer for him to recite Gilbert and Sullivan as well - even though as the script notes: "[T]hese are none of the people who, in their previous life, would have enjoyed the idea of an impromptu Gilbert and Sullivan recital."
Act II
Seven years later, it turns out that the survivors ended up sticking together and forming a tightly-knit theatrical troupe.
When Gibson has a Freak Out over the fact that he doesn't remember agreeing to sell Heretic Homer, Sam grabs hold of him and snaps him out of it. Then Maria and Coleen rally around him as well, reassuring him that it really was just a bad batch of alcohol throwing off his memory.
Act III
There is something distinctly uplifting about the fact that our "current" pop culture is still remembered, even in a drastically changed state.
We never find out what happened to the survivors, but little things like Jenny's notebook, the forehead touch, and the specific use of Gibson's Gilbert and Sullivan song give the distinct sense that the play is tied directly into their legacy - not just the general legacy of humanity.
The names read during the chorus are actual names. Their owners may be dead, but they have not been forgotten.
The moment where Bart finally hears the voices of his family encouraging him to stand up and fight.
