It was once the convention of clichéd Hollywood movies that when somebody got bonked on the head, it resulted in convenient amnesia, which would be resolved by another blow to the noggin. In Amy Schumer’s new romantic fantasy, a well-meaning but strangely off-kilter comic critique of unrealistic standards of female beauty, it instead causes a flood of unaccustomed self-confidence, which is, of course, eventually eliminated by another blow that brings her character back down to earth and invites a rather insipid third-act moral about being yourself.

Renee Barrett (Schumer) is introduced as a plain but spunky young woman working in the basement online department of cosmetics powerhouse Lily LeClaire, alongside good-natured slob Mason (Adrian Martinez). She thinks herself unattractive because she doesn’t fit the image of beautiful women who populate not only the covers of glossy magazines but the glitzy offices of the firm she works for, now run by Lily’s (Lauren Hutton) granddaughter Avery (Michelle Williams, using a hilariously whispery baby-doll voice).

So while joining with her equally “plain” girlfriends Vivian (Aidy Bryant) and Jane (Busy Philipps) to make a dating video—an effort that gets a humiliating zero views—she decides to take action, joining a stationary bike class to lose weight. Unfortunately the apparatus collapses beneath her. (The implausibility of this is overwhelming: the script seems to suggest that she’s elephantine, which is clearly not the case.) And in a second tumble she hits her head, leading her to see herself as a super-beauty in her own mind and deal with others as if they shared that perception. We’re never shown how Renee now sees herself physically, but the bewildered reactions of those she now interacts with are amusing enough. One such is Ethan (Rory Scovel), whom she meets at a dry cleaner’s and insists on sharing phone numbers with. The two soon become a number of a different sort.

Meanwhile she decides to apply for the receptionist’s job at the Lily LeClaire corporate office, and is hired not just on the basis of her utter assurance that she belongs with all the slinky beauties in the place but because the company is about to start a line of products designed to appeal to “regular” customers at outlets like Target, and she can offer suggestions about what the “non-elites” will respond to. She not only becomes a trusted advisor to Avery and a prospective spokesperson for the new line of products, but catches the eye of Avery’s playboy brother Grant (Tom Hopper).

But the experience has its drawbacks. Renee’s over-confidence leads to a breach with Vivian and Jane as she pushes them to change, too. And when, right before an important conference, she clumsily crashes into a shower window after becoming flustered over Grant’s attention, her confidence evaporates, and she’s thrown into a renewed funk about her looks, even threatening to break up with Ethan. Whatever lesson can she—and we—learn from all this?

Schumer gives her all to the formulaic script by Abby Kohn and Marc Silverstein, who specialize in romantic comedy conventions, though here they try to add some messages associated with the actress’ prior work satirizing common presumptions about beauty, though they turn out to be rather mixed, leading to lots of overstatement (as in a wet tee-shirt contest). They also directed, apparently giving their star very free rein—many of Schumer’s riffs seem to be improvised, and she delivers them with an energy that can come across as manic.

The rest of the cast is pretty much overpowered by her, but Williams cuts a delicious figure of privilege clueless about ordinary folk, while Scovel makes an ingratiatingly laid-back romantic interest (though, to be honest, there are occasional hints about layers to Ethan’s character that go unexplored). Martinez gets some juicy moments, and Emily Ratajkowski a few nice ones as a stunning woman who teaches Renee that looks aren’t everything. The technical crew bring their A game to the enterprise, with Florian Ballhaus’ cinematography complementing William O. Hunter’s production design and Debra McGuire’s costumes. Only Tia Nolan’s editing feels a mite slack, though that might be the result of the direction.

“I Feel Pretty” has already aroused some online criticism of fat-shaming, and it does open itself up to accusations of insensitivity, not only about what used to be called “plus-size” women but to thin-as-a-rail, supermodel types as well. Such is the movie’s uncertain messaging that a viewer might request a tap on her skull after seeing it, hoping that it will bring about a two-hour bout of forgetfulness so that she won’t recall having sat through it. Setting aside such larger objections, one can dismiss it as simply not as funny or insightful as it ought to be.