Everyone can tell that Abby (played by screenwriter Jennifer Westfeldt) is adorable. Her parents dote on her. A jittery subway mugger is disarmed by her – literally. She has not managed to sell a single membership at the health club where she works, but she has the affection, esteem, and devotion of everyone who works (and works out) there. When Ira (Chris Messina) wanders in, she tells him not to bother with a membership and he is immediately smitten.

Yes, everybody loves Abby. That is a problem for Ira, who has to learn to trust his feelings for her and hers for him. But it becomes a problem for the audience, too. Westfeldt as screenwriter is a little too much in love with the character she has created for Westfeldt the actress, but a strong cast and its willingness to go beyond the usual conventions of romantic comedies keep us rooting for the young couple to find a happily ever after ending.

Just after they meet, Abby impulsively proposes to Ira and he accepts. Up to that point, Ira has had a terrible time making decisions. His psychotherapy, his doctoral thesis, and his romantic relationship have all stalled. He overthinks everything to the point of implosion.

But Abby is irresistible, because she appeals to Ira’s heart, not his head, because marrying her represents action and progress, and because he loves the feeling that he makes her happy. Most important, she represents that Life Force often found in romantic comedies, which frequently focus on an uptight character learning how much more there is to life from a free spirit.

As with her first film “Kissing Jessica Stein,” Westfeldt has written a clever screenplay with some zingy one-liners and sharp characterizations. It flirts with farce, even satire when the main characters and their multiple therapists all sit down in a big circle to talk things over. The final act becomes over-plotted when old and new relationships threaten to derail the happiness that so quickly came to Ira and Abby.

What keeps it all on course is its grounding in some important insights about relationships that are overlooked in movies that fade out after the couple gets together. This movie begins where most comedies end, allowing it to gently raise some thoughtful points about relationships. The very thing that first draws Ira to Abby, her ability to see the best in him, becomes the thing that frightens him. Does he love her for who she is, and not just for the vision of himself he enjoys in her eyes? The very thing he first loves about her, her ability to be happy, scares him, too. If she can be so easily delighted, how can he be sure he is special to her? Ira discovers that what can be most terrifying for him is not loving but allowing himself to be loved.

The movie benefits from an exceptionally strong line-up of supporting characters beautifully played by a top-notch cast. Fred Willard and Frances Conroy are Abby’s jingle-writer parents, so endlessly cheerful that they make Santa look grumpy. Ira’s therapist parents are played by Judith Light and Robert Klein, brittle as the ice clinking in their highballs. The hilarious parade of counselors includes “Seinfeld’s” Jason Alexander, “Saturday Night Live’s” Chris Parnell and Darrell Hammond, and the always-exquisite Donna Murphy. Maddie Corman displays all the expected neuroses but also some unexpected vulnerability as Ira’s ex. Ramon Rodriguez is nicely disconcerted as the subway mugger. Each of the characters captures our interest and attention. And both as screenwriter and as star, Westfeldt keeps the center of the story sweet and the movie as impossible to resist as its irrepressibly warm-hearted heroine.

Parents should know that the movie includes strong languages, drinking, references to drug abuse, and sexual references and non-explicit situations, including adultery.

Viewers who see this movie should talk about why it was so easy for Abby to connect to people. Why was it so hard for Ira to feel that he deserved love? What should they have talked about before getting married?

Viewers who enjoy this movie will also enjoy “Annie Hall” and “Breakfast at Tiffany’s.”