Plot
Jane Goodale voices over the images of a scientific experiment showing a bull won't mount a cow twice, even if her scent is changed. Until recently, she believed men are all like the bull, but she discovers it is not always true.
Jane is a production assistant for a recently syndicated talk show. Host Diane Roberts is always looking for ungettable guests, like Fidel Castro. Eddie Alden is the producer and a womanizer, much to Jane's amicable critique.
Eddie bulletin board poster for a roommate keeps getting damaged by disgruntled exes. Offering Jane the room, she turns it down vehemently. Meeting the show's new producer, Ray Brown, she is immediately smitten. Telling her friend Liz about him, they discusses her bad luck with men.
Meanwhile, Jane's sister starts fertility treatments. Ray calls Jane, they spend an evening together and finally kiss. Ecstatic, the next morning she calls Liz, who gives her advice on Ray and his girlfriend Dee (with whom he has trouble). Ray and Jane seem to be very much in love.
As the relationship evolves, they decide to move in together. Jane gives her landlord notice; when Ray tells his girlfriend it is over, he does not say anything about another woman. Distancing himself from Jane while she is packing to move, he breaks it off over dinner, leaving her devastated.
The next morning at work Jane announces she's moving in with Eddie in revenge. She learns to deal with the many women in Eddie's life and they bond over scotch and leftovers. Jane starts researching her theory of men after reading an article about the old cow syndrome. Liz works at a men's magazine, so proposes Jane write a column about her theory, under the pen name Dr. Marie Charles.
The column, dealing with men's insecurity and dishonesty, is a success. Everybody wants to meet Dr. Charles, including Diane. At a Christmas party, Ray tells Jane he misses her, asking her out for New Year's Eve, but stands her up.
When Jane shows up at a party looking for Eddie at midnight, she can't find him and leaves in tears. He spots her across the crowded room, but can't reach her. Back at the office, when Ray starts to apologize, Diane interrupts wearing the shirt Jane bought him. Diane is "Dee," and they are back together.
As the board meeting is about to start, Eddie makes sure Jane isn't crying going in, but she acts strangely, so he covers for her. When Ray gets emotional talking about a Gérard Depardieu movie, Jane spills her guts over his inability to show empathy for her broken heart. After the meeting Diane, unaware of Jane's relationship with Ray, gives her advice on how to win her boyfriend back, telling her how she did it.
At a bar, Liz follows Dr. Charles's advice to not fall for the same kind of guy anymore. Jane and Eddie argue over Dr. Charles' advice. At home she tells him she has to believe the theory because otherwise she fears men don't leave women - just her. Eddie comforts her, saying Ray is not the last man she'll ever love, and they fall asleep together.
The next morning Eddie wakes up content and comfortable while Jane freaks out. He suggests she not overanalyse it, saying he is happy they slept the whole night together without it leading to sex. Jane tells Eddie he will show his true colours and hurt her soon, but he suggests it is not about him, but rather her attitude is the problem.
Jane's brother-in-law calls, as her sister had a miscarriage. At the hospital she sees their true love and tells Diane that Dr. Charles will be on her show. Originally, the interview was meant to be via telephone, but Jane changes her mind mid-way and goes on the stage. She tells the audience that there is no Dr. Charles (Eddie leaves at this point) and the theory is ridiculous because she was hurt and needed to blame men for her pain.
Jane goes after Eddie and tells him she found new love. He doesn't answer, but kisses her passionately, with Van Morrison's "Someone Like You" playing in the background.
