Honestly I am watching this movie asking myself, "Why is this a good movie?" It isn't terrible, but I never once get into the characters. I never once get into their drama. I feel like I am just watching a 1950's orgasm on screen. Every scene brings a new famous song, which means you will hear a song play every 1 to 5 mins in this movie. To me, this is member berries. This movie completely holds on the idea of nostalgia.
It is intended to make the audience yearn for those old days. There is no character development, there is no complex story here. In terms of how it is shot, the entire film is only 40% lit, so most stuff is just in darkness. Not sure why, but okay. The lighting is just terrible. The acting is not great. I also feel like this movie simply is not aging well. It does not feel like a masterpiece.
I certainly cannot put AG in with films like Apocalypse Now or The Godfather. This movie is overrated at this point, sort of like Star Wars. You can see American Graffiti, or you can just go to an 'oldies-themed' diner and get the same experience.