There’s an assertion frequently made by certain Yalies, often the high-achieving, perfectionist, neurotic ones. It’s uttered in January or February, before they’ve landed their high-paying internship or job. “I don’t know what I’ll do,” they claim. “If worst comes to worst, I’ll just live in a box this summer!”

“Adventureland” chronicles the realization of this worst fear. The excellent Jesse Eisenberg stars as James Brennan — the kind of guy everyone refers to by last name — who just graduated as a Renaissance studies and comparative literature major from Oberlin. After his parents have some financial mishaps, Brennan must forgo his planned European exploration in order to earn money to pay for grad school at Columbia.

But it turns out his degree isn’t worth much in the labor force, and Brennan is stuck spending the summer working at Adventureland, a run-down amusement park where a muscular old man might try to procure a giant stuffed panda for his son at knifepoint. A classic coming-of-age plot emerges: Brennan falls in love, makes new friends, comes to terms with his family and finally figures out his goals and how to achieve them.

The result may surprise even the highest achieving Yalie. “Adventureland” makes the ‘worst case scenario’ look like a dream job. As Brennan uncovers his true self in the most banal of scenarios — lousy dates at local diners, “two for Tuesday” nights at a trashy bar and cleaning children’s vomit out of games and rides — the audience can’t help but be … envious. The adventures aren’t perfect, and there’s a whole lot of pain, but the characters are so vibrant and impulsive and the environment is so immersive that you never want to leave. They all seem so alive — there’s a certain poetry to the movie that simply resonates.

The theme of finding direction and purpose not only is central to the plot, but also is mirrored in the career implications of two main players: writer/director Greg Mottola and female lead Kristen Stewart.

After writing for three of the best TV comedies of the decade (“The Comeback,” “Arrested Development” and “Undeclared”), Mottola has now directed two feature films — “Superbad” and “Adventureland.” In addition to his apparent love for odd portmanteau titles, Mottola has cemented his reputation as a unique and authentic portrayer of young adult relations, whether romantic or otherwise. Each of his characters, even the most minor, has unexpected depth. One of the most affecting characters in the film only occupies 10 minutes of screen time: Brennan’s father, emasculated and powerless after a demotion, is a real human being.

After “Superbad,” however, Mottola was expected to go down the Apatow/Rogen comedy route, and “Adventureland” was marketed as such an endeavor. On the contrary, “Adventureland” is, if anything, a drama. Mottola covers heavy themes and impacting moments with subtlety and precision.

Whereas Mottola has carved out a new path for himself, Kristen Stewart has cemented her identity as “The Girl from ‘Twilight.’” Stewart plays Em with Bella Swan’s characteristic hovering posture, shifty eyes and half smiles. In fact, she plays Em almost as a hypothetical Bella — what if Bella had negligent parents, bad role models and worked at an amusement park? She would do drugs! She would be cynical! She would have affairs with married men!

Nevertheless, there may be no one better suited than Stewart for this type of role. Even if her character doesn’t believe in true love herself, she adeptly convinces the audience to — and it’s just a tad more relatable than eternal vampire lust.