Covered Up: Most of the soundtrack consists of popular artists of the time performing covers of lesser-known Steely Dan songs.
The soundtrack also includes The Offspring's version of AFI's "Totalimmortal", which was released as a single - At the time The Offspring had just released one of their most commercially successful albums (Americana), while AFI were relatively lesser-known since they were on an independent label and hadn't had any charting hits of their own yet.
Critical Research Failure: One of Charlie's sons exclaims "Man, how the hell can they call Pluto a planet, man? What kind of planet has an elliptical orbit? This shit don't make sense!" Almost all planetary orbits are at least a little elliptical. A true oddball orbit would be a perfect circle.
Fridge Horror: When Hank first surfaces, one of the first things he notices is that he's carrying a gun. If Hank's response to disrespect is to nearly drown a little girl and smash a car into a barbershop, it's a good thing nobody ever took it further than that.
Hilarious in Hindsight: One of Charlie's sons complains about Pluto being considered a planet. Pluto was demoted in 2006, six years after the movie was released.
Jerkass Woobie: Hank. He's the one who has had to deal with all of Charlie's repressed rage for twenty years or so, and never gets out to express it. He also notes to Irene that before Charlie's wife left him, their personality was more integrated; when she left, she left both of them, and that was the point when Charlie split off the Hank personality and locked it away. While obviously no excuse for his actions, it does make you feel for him, especially when he begins crying.
The Woobie: Charlie. The second you see his kids being born, you will feel sorry for him. It only increases as the film goes on, and you learn that the entire town is laughing at him behind his back and he knows it, but is too nice to do anything about it. Becomes a bit of an Iron Woobie, because regardless of who their real father is, Charlie loves his kids. He can take abuse directed at him, but when it comes to his kids, even his doormat status prompts him to defend them without even thinking.