The inspirational Post-its on her bathroom mirror - e.g., "Where there is no struggle, there is no strength" - are of little help in a situation where she is no longer a contender.
Lisa is dating Matty (Owen Wilson), a fun-loving pitcher for the Washington Nationals, whose patter is as loopy as his curveball. Is he Mr. Right or Mr. Right-now? Lisa doesn't know. The upside: Matty's fastball averages 94 m.p.h. and he makes $14 million a year.
On the fence, Lisa goes on a blind date with George (Paul Rudd), lately the subject of a federal investigation. He is out of a job at his father's company and on the outs with his girlfriend.
Where Lisa sees failure as a growth opportunity, George sees it as an occasion to take a belly flop into the pool of self-pity. If there were a dating Hall of Infamy, their dinner likely would win the most votes.
In the physics of Brooks' movie, what attracts George to Lisa is her native confidence. What attracts Lisa to Matty is his self-assurance, which compensates for her loss of same.
Yet Brooks' counterintuitive takeaway - heretical for a Hollywood movie - is that confidence and assurance don't make people more attractive. To paraphrase a line from Broadcast News, what's attractive is how they face their insecurity and desperation. This is not, by any stretch, your formula romantic comedy.
It is a keenly observed movie about loss of identity and finding love, in which Brooks serves up funny-ouch humor with slapstick heartbreak. He elicits a nuanced performance from Rudd, who in his swings from fatalism to hope recalls Jack Lemmon in The Apartment.
Witherspoon, her sunshine in eclipse, has a trickier role as the lost gal struggling to find herself. Optimism has so long been the hallmark of Witherspoon's persona that it's a shock to see her play someone embracing that unwanted squatter, pessimism. "Courage is the mastery of fear" is Lisa's mantra, but Witherspoon conveys how Lisa has lost faith in such motivational scripture.
Wilson's Matty gets the funniest lines and the sharpest observations ("Why do girls always look so pretty the minute they're not so sure about you?"). But while his puppyish enthusiasm gives the movie its bounce, he and Witherspoon generate little heat. Apart from butter-blond highlights and skill on the diamond, they have nothing in common.
The film's nicest surprise is Tony Shalhoub, a psychologist Lisa consults, who offhandedly delivers the film's moral. Its biggest disappointment is Jack Nicholson (a Brooks regular so terrific in Terms of Endearment, Broadcast News, and As Good as It Gets), as George's father. (In the film, set in Washington and shot in D.C. and Philly, Nicholson's office looks to be catercorner from City Hall.)
Kathryn Hahn is lovely as George's very pregnant and very supportive secretary.
In the end, Brooks suggests, courage isn't the mastery of fear; it is the management of fear. How Do You Know succeeds on its own terms because it doesn't force a false smile or an unearned epiphany on its material.
Contact movie critic Carrie Rickey at 215-854-5627 or email@example.com. Read her blog, "Flickgrrl," at http://www.philly.com/philly/blogs/flickgrrl/