The makers of The Wackness would like us to visualize its setting inside a concise set of coordinates: New York City in the early ‘90s, the era of Rudy Giuliani (remember him?), when the streets were filled with wildly inventive hip-hop, “a time when Tupac and Biggie were alive but Kurt Cobain had just died.” OK got it. But writer-director Jonathan Levine’s ingratiatingly funny comedy does more than just riff on a time and place– it belongs to that great fraternity of novice-and-mentor films, à la Cinema Paradiso, in which an inexperienced person comes of age with the help of a kindly and worldlier friend. In most cases, the inexperienced character is young and the mentor older, but when it comes to The Wackness we’ve got our doubts.

It’s the summer of 1994 in Manhattan, and Luke Shapiro (played by Josh Peck) is girlfriend-less and feeling out of it, even though he’s making money and networking like crazy in his retail weed business– he sells marijuana out of a New-York-style pushcart on the street, unlikely as that may seem. Lonely and anxious is no way to spend his last summer before heading off to college. On top of everything, newly elected Mayor Giuliani has promised to crack down on raucous street life as part of his plan to make New York “safe.” Safe from what?

Luke’s battling parents send him to a therapist, Dr. Squires (Ben Kingsley), whose own life could use some tinkering. His wife Kristin (Famke Janssen) has a roving eye and her daughter Stephanie (Olivia Thirlby) is so much brighter and more capable than her mom and stepdad, she ought to be taking care of them. If this sounds familiar, you’re right. Probably a dozen coming-of-age movies get made every year with an identical premise. It’s a youth-market cliché– the screwed-up kid who in reality is far more viable than the authority figures around him. But filmmaker Levine, who apprenticed with Paul Schrader, creates such rich, complex characters, with such lively dialogue, that Luke’s predicament suddenly seems novel. The only things the kid lacks are experience and confidence.

Luke lays his heart on the line to Dr. Squires: “I’m mad depressed, yo.” The shrink comes back with advice on conducting “a beaver hunt, a pussy quest.” This is exactly how an aspiring young writer fantasizes an exchange between him and his therapist– it takes place here through the magic of movies. Before long, they’re going out to bars together in the last days of New York State’s 18-year-old drinking age, smoking blunts, and Luke is dubbing mixtapes for the doc. In fact, the shrink is such a case of arrested development he should be paying Luke for advice, which in a way he does– the kid ends up paying his psychologist bills with ganja and taking Dr. Squires with him on his rounds. And then Luke falls in love with Stephanie, the shrink’s stepdaughter. Word!

Sir Ben gets right down into the role of the happily immature witch doctor and grovels in it. Dr. Squires is less like Kingsley’s character in House of Sand and Fog and more like his Fagan in Polanski’s Oliver Twist: a frother on a bender, pathetic one moment and hilarious the next.

Truth to tell, Levine and Nickelodeon TV star Peck belabor Josh’s loneliness a little too much. He be illin’ more than necessary. “You just look at the wackness,” observes the sagacious Steph, Luke’s dream date. Ahh, first love. With the right touch it’s one of the movies’ can’t-miss hot buttons. Thirlby (United 93, Snow Angels, Juno) is brilliantly sensual and the shower scene is terrific.

Around the edges, The Wackness is stuffed with vivid characters like Luke’s customers Union (Mary-Kate Olsen) and Eleanor (Jane Adams), and his Jamaican connection, Percy (Method Man). And of course a suture tray full of vintage hip-hop by the Notorious B.I.G. (“The What”), A Tribe Called Quest (“Can I Kick It?”), R. Kelly (“Bump & Grind”), Wu-Tang Clan (“Tearz”), Raekwon & Ghostface Killah (“Heaven & Hell”), et al. By the time Luke resorts to taking the Big Swim off Fire Island in the last reel, we know he doesn’t really need to go through with it. It’s just an exercise. So is The Wackness, but it’s an exercise in style and wit, two commodities that never go out of fashion.

THE WACKNESS (3) Directed by Jonathan Levine. • Starring Josh Peck, Ben Kingsley and Olivia Thirlby. • R, 95 min. • At the Osio Cinemas.