It's also an interesting portrayal of class angst, of thwarted expectations. I love the setting of the amusement park where people go to have mindless fun, and all the carnies who work there are just miserable misfits. These poor overqualified eggheads, working in a place full of dummies. That's America for you, a huge amusement park that craves entertainment, and is derisive of intellect.
Adventureland made me feel nostalgic for my hormone-riddled youth. Set in the eighties, it makes one wonder what were we thinking ("Amadeus, Amadeus, Amadeus"... ).