The initial scenes establish that Joanna Stayton (Goldie Hawn), is a spoiled brat who always gets her way, the ultimate rich bitch, and the pampered wife of pretentious socialite Grant Stayton III (Edward Herrmann).
Using Roman numerals after your name is Hollywood shorthand for "pretentious snob", and Grant is that, and self centered to boot, however, Joanna is far worse. She is not only snobbish but also idle, pampered, sharp-tongued, impossible to please and unfailingly rude to anyone she considers her social inferior, which is virtually all of the human race. To describe Joanna as unsympathetic is a huge understatement, a better description would be "prize bitch".
When Grant's luxury yacht develops engine trouble, Grant is forced to put into the small Oregon coastal town of Elk Snout for repairs.
While the huge yacht is in port, Joanna hires Dean Proffitt (Kurt Russell), a poor carpenter who has just moved to Oregon, to build better shoe storage for her closet in the yacht. Dean is a skilled craftsman, rather picky about what he uses, such as the wood that should be used to protect the leather from salt spray in a ship. Joanna is also not impressed by his taking so long, as he designed intricate shelves that confuse and annoy her.
An early funny scene in the movie has Joanna lecturing Andrew the butler ( Roddy McDowall), on why the caviar he had just delivered her was no good, while Dean, standing in the background, has his tape measure pointing suggestively skyward.
When the work is complete she refuses to pay him in a dispute over the quality of his workmanship,
claiming that the closet is not up to her standards. In the ensuing argument Joanna loses her temper, pushes Dean overboard and throws his tools after him.
The yacht crew has long ago gotten used to keep quiet and accept the guff from Joanna and Grant, despite that they have been treated like dirt, particularly family butler Andrew.
After a typically stormy dinner that night, Joanna drops her wedding ring behind a seat on the deck. In reaching for it she loses her balance and falls overboard.
A garbage boat rescues her but there is a problem: she is suffering from amnesia and cannot remember anything of her former identity. This we learn as Joanna is interviewed as she is wheeled into a psychiatric hospital.
The following morning Grant returns to port, and finds Joanna is safe in a hospital but she has lost her memory, while her personality remains as nasty as ever.
Grant, who is weary of Joanna, pretends that he does not recognize her, seeing his chance to be rid of her and to lead a playboy bachelor lifestyle on the yacht.
When news of the unidentified amnesiac is televised throughout the city, a still angry Dean recognizes her picture and believes his opportunity for revenge has come. In a stroke of retributive genius, Dean shows up at the hospital audaciously posing as her husband and identifies Joanna as his wife "Annie". He tells her that she's his wife and the mother of his four unruly boys.
His motive is not only payback for the way in which Joanna treated him but also his need for someone to do all the housework, as Dean is skilled as a craftsman but less accomplished in parenting and housekeeping. He is a widower with four young sons and finds it difficult to cope. The kids have missed a woman's touch in their home for nearly five years since their Mom died. Since the death of their mother his attitude towards his children and his household has been one of benign neglect. The boys have become undisciplined and badly behaved and the house looks like a war zone.
Dean's intention is to get compensation for his unpaid work from Joanna being the household maid for a while. He figures on crediting her for 25 dollars a day. He assumes she'll be good for cleaning up around the house and looking after his four sons. The sons agree to the hoax, so Dean brings Joanna into his highly unkempt home and gets her to do all the chores.
Although Joanna cannot recall her previous life with Grant, she is not convinced that she really is Dean's wife, especially as she turns out to be totally unskilled at cleaning and cooking. There isnt any sexual attraction on either side, so she sleeps on the couch in the living room and he keeps his bed.
She asks Dean questions like where did we meet, what jobs did I have, and his answers are pretty low class redneck, so the muses to herself, I was a short, fat, slut? Whatever her questions, Dean manages a cover up with some silly story.
When she gets curious about why there arent any pictures of her anywhere, Dean arranges for one of his buddies to modify Deans original wedding pictures by inserting Joannas face replacing his first wife.
Later on, when Joanna discovers that she is fluent in French, Dean has to make up a tall tale to explain why.
Joanna, finally believing she is Annie, struggles to become a good housewife and mother. She accepts her role as the woman of the house. Gradually, however, she gets used to her situation, she gets good at it, Dean even begins to fall in love, as Joanna's hidden talents come out.
While overwhelmed at first by having to do unfamiliar work, including cooking, while struggling to remember this family, Joanna slowly works things out. Joanna brings some discipline back into the lives of father and sons.
She is able to moderate the wild, "bachelor's hall" lifestyle that Dean has set up for himself and his sons. The boys accept a curtailment of their freedom, which at first they resent but slowly appreciate. A breakthrough with the kids comes when she sticks up for them against a bullying school teacher. A breakthrough with Dean comes when she finds he is earning extra money at a menial moonlighting job on a night that he says he goes out bowling with the guys.
Joanna gradually comes to appreciate Dean's good qualities and to sympathize with little people she had previously dismissed as worthless.
Dean finds he's got a dilemma to solve, as he too begins to appreciate her. He first feels he truly cares for her when she gets a poison ivy rash and he does everything a loving husband would do to make his wife feel better.
She is crucial help to him in landing a construction job for a miniature golf park, she suggests a theme of famous world landmarks, and prepares sketches that sell the concept to the investors. He's missed having a female companion with intelligence. He decides to tell her the truth, but he doesnt get his confession out fast enough, she jumps the gun to tell him she knows the secret. So once again he lies, he apologizes for forgetting her birthday instead, and takes her out on a fun birthday date with lots of music and singing.
As they come back home that night, Joanna realizes she is truly happy with him, and they have their first passionate all night encounter as part of the birthday celebration.
Of course the situation remains tricky, since it is endangered if Joanna recovers her memories.
Meantime, Joannas mother (Catherine Helmond) has been hounding Grant on why she has not heard in weeks from her daughter, makes credible threats, and flies out to stay at the yacht.
So Grant, who left her at the hospital originally, is pressured by his mother in law to retrieve her.
Grant finds her easily, drives in his limousine to the house she shares with Dean, and waits.
Joanna comes towards house, sees Grant, and her memory functions well enough that she says, Hi, Grant. With that trigger, her memories rapidly return to her and she leaves Dean to rejoin Grant and her old life of material privilege on the yacht.
However, Joanna is no longer the woman she once was and she misses Dean and the children. She hates the wealthy snobbishness represented by Grant, her own mother, and the psychiatrist. Her mother (Kathleen Helmond) is constantly using the advice of a fashionable psychiatrist (Henry Alan Miller) on how to treat her daughter. She asks for beer when she is offered champagne, and she spends time in conversations with the cook, the crew, and the butler.
The film is clearly intended as a satire on the ways of the ultra-rich. There is a sharp contrast between Joanna's idle, pointless existence before her transformation and her fulfilling, useful life as a blue collar housewife after it.
Soon after the yacht departs Elk Snout, Joanna finds out that Grant knew where she was all along, and had abandoned her in the hospital. Furious, she commands the skipper to reverse course and return towards Elk Snout. Meantime, Dean and his kids are unhappy at doing nothing to get her back, and decide together to give it their all in one last grand effort. They pull some favors from buddies and get a Coast Guard boat to chase after the yacht, as long as there isnt any actual call for the Coast Guard boat to chase anyone else.
As the two vessels approach each other, the Coast Guard receives an emergency call, and Grant on his yacht fights for control of the bridge, overpowering both the skipper and the butler, and the boats start to veer away from each other. Dean jumps off the ship, Joanna jumps off hers, and naval protocol requires both ships to circle back to pick up the men overboard.
Needless to say, there are hugs and kisses and reunions all around. Joanna leaves Grant, and begins a happy life with Dean and the boys, only now on her yacht, instead of Dean's shack.
In the last scene, Christmas lists are being prepared. One of the boys asks how does one spell Porsche. Dean asks, What can I give you? You already have everything!.
Her answer is You could give me a little girl.