Featuring Tom Hanks as a downsized mega-mart employee who tries college in midlife and Julia Roberts as his unlikely prof, Larry Crowne is a bewilderingly bad movie. Maybe the stars are no spring chickens, the career dilemma they're both trying to resolve here. But these are still people with resources —options, you know? They don't need to grab at the first crummy, amateurish script that comes down the pike. Even if it's written by—cough, cough—Tom Hanks, in tandem with Nia Vardalos of My Big Fat Greek Wedding and not much else.

Hanks also directed, increasing the bafflement. He's done it before—in episodes of HBO's Band of Brothers and From the Earth to the Moon, both of which he also produced. Same goes for 1996's negligible (but not bad) That Thing You Do! As filmmaking, none of them would have cost Orson Welles a nanosecond's sleep, but at least they made sense as passion projects. This one? Not so much, unless Hanks was kidding himself that a heartwarmer about average folks pasting things together was Capra for these times. Too bad that what he knows about the "little people" wouldn't fill Tom Thumb's jockstrap.

The story Etch-a-Sketches along from one inept contrivance to another. When we first meet Larry, he's a bustling drone bee in a big-box store, fatuously sure he's going to be named Employee of the Month (again) when he's called in to learn he's being fired on account of his lack of a B.A. Yet he's also supposed to be a 20-year Navy vet, a c.v. gauchely introduced to give this doltish Joe Ordinary a dollop of belated true grit.

Urged on by his next-door neighbor (Cedric the Entertainer, who's looking mighty bored these days with playing the Irrepressible Black Guy for white people), Larry enrolls at a local community college, where he's improbably adopted by a foxy gamine named Talia (the appealing Gugu Mbatha-Raw). She not only gives our hero a fashion makeover but invites him to join her fun-loving—get this—scooter club, making for lots of zesty, put-putting L.A. filler scored to the likes of Tom Petty's "Running Down a Dream." You know how kids today just love hanging out with unemployed old dorks who've got the conversational skills of armadilloes.

As for Mercedes "Mercy" Tainot (Roberts), she's stuck in a bum marriage with a writer husband (Bryan Cranston) who's given up making a living for the joys of surfing the Web. It says a lot about the script's keen grip on modern life that the proof Hubby's a skunk is his sneaky yen for online porn—which isn't even porn, just pretty timid cheesecake. Gotta protect that PG-13 rating, after all. Watching a gifted actor like Cranston (Breaking Bad") rasp his way through a straw-man part like this one makes your heart go out to his wallet.

Then Larry enters Mercy's classroom, and magic happens. Except it doesn't, really: These two stars would be better off enrolling in a chemistry class instead. Apparently, we're meant to swoon at the mere idea of "Hanks and Roberts—Together at Last," but honestly, who was pining for it? It's no help that, while Larry's age is kept vague, Hanks is clearly hoping to pass for a few years younger than the 54 he is in real life; you wince at the makeup and what looks to be the bad dye job on his hair. As for Roberts—though she's still got That Smile, which doesn't get much of a workout here until the climax—she not only looks gaunt but seems eerily unaware of how humongously unpleasant her character's behavior is for about nine-tenths of the movie's running time.

Because her acting has stayed unblemished by anything resembling craft in 20-plus years as a box-office draw, Roberts needs lots of directorial TLC to sparkle—something you'd expect this particular director to be attentive to. But Hanks leaves her stranded in bit after toxic bit that gives Mercy the charm of a ranting bag lady with a graduate degree. She's hailed at movie's end as a "great" teacher, but we see an atrocious one: peevish, bored, disdainful and incompetent. (It's fairly incredible that nobody thought of giving Mercy a scene in which she's actually shown improving a student's communication skills.) About the only thing that seems to give this dame pleasure is malice—e.g., when she gleefully whoops it up at seeing Cranston pulled over for a DUI after a marital spat. Maybe the young Katharine Hepburn could have pulled off the contemptuous-shrew routine and made it charismatic, but not our Julia.

And so long as we're into invidious comparisons, isn't it fun to remember how Hanks used to be called the boomers' Jimmy Stewart? He even deserved the accolade at one point, but when Stewart was middle-aged, he didn't only make mush like Harvey. He played the richest and darkest parts of his career for Hitchcock, Anthony Mann and Otto Preminger, too. Even more than Stewart, Hanks is in a position to do whatever he wants, and yet the last real acting challenge he took on was Saving Private Ryan—13 years ago. Larry Crowne is his project from start to finish, but he's so uninterested in his own performance that it looks like a paycheck gig instead. If anyone under 30 goes to see the damn thing, which isn't likely, I swear they're going to wonder why he was ever a star.