NOTE: This spoiler was submitted by Dukes.
The film begins with Paige (Rachel McAdams) and Leo (Channing Tatum) coming out of a movie theater. It is snowing. They get in the car to drive home, and they are laughing and joking as Leo sings along to the radio. At a stop sign, Paige says she heard that sex in cars is conducive to pregnancy. She unbuckles her seatbelt to lean over and kiss Leo.
At that moment, a huge dump truck rear-ends their vehicle, sending Paige crashing through the windshield in slow motion. As they are rushed to the hospital, Leo’s voice says “My theory is that there are moments of impact and high intensity that end up defining who we are.”
Flashback to the day that Leo and Paige first met. They are both waiting in a long line for a parking pass, and Leo follows Paige out to her car. He points out that they live in the same parking zone, and says that means they should go out on a date. They head to Café Mnemonic where they laugh and talk and feed each other truffles.
A montage of their relationship follows. Paige is working as a waitress, and she’s sick with a cold, so Leo leaves her a box of treats to make her feel better. Then they are driving in the car, laughing and joking with each other.
Back at the hospital, the doctor explains to Leo that they are keeping Paige in a coma to allow her brain to heal. Leo’s voiceover says “Each of us is the sum total of every moment we’ve experienced and every person we’ve know.”
Flashback to Leo asking Paige to move in with him, spelled out in blueberries on her pancakes. Then flash to their wedding day. Both wrote their vows on Café Mnemonic menus. They were married in an art museum, and had to run away from the security guards as soon as they were finished. Flash to Paige working on her sculptures in her art studio. Paige is extremely stressed about the huge commission she won, and Leo helps her de-stress by tickling her. They make love on the floor.
Back at the hospital, Paige is finally brought out of her coma. Leo is waiting to speak with her, and she seems okay, until she asks “Was anyone else hurt, doctor?” to Leo. She doesn’t recognize him. Leo explains that he is her husband, and she stares at the ring on her hand in shock. Leo’s voiceover says, “Moments define who we are. What if one day you could no longer remember any of them?”
Later, Leo is sleeping in the waiting room of the hospital. Paige comes and wakes him, and asks if he wants to get something to eat in the cafeteria. As they eat, she asks him about her life. He explains that they live in the city, and she is a sculptor. She only remembers being in law school.
Cut to Leo discussing the situation with his friends. They joke and say that it’s actually a good thing Paige lost her memory, because now she won’t remember any of the stupid things Leo has done.
Back at the hospital, Leo is surprised to see that Paige’s room is empty. She’s been moved upstairs to the VIP donor wing. He goes up to her new room and finds Paige’s parents fussing over her. It’s obvious that they have never met Leo. They want Paige to come home with them, but of course, Leo wants her to stay with him.
At the cafeteria again, Paige asks Leo what is going on. Leo says that she hasn’t spoken to her family in five years. Before Paige and Leo met, Paige had a big falling out with her parents. Her father was angry that she broke off her engagement with Jeremy and dropped out of law school.
Paige’s parents try to take her home, and Leo begs her to stay. Paige says, “But I don’t know you. I don’t even know that we were really in love.” Leo plays her a voicemail that she left for him, but she’s not totally convinced. Leo says, “You owe it to yourself to honor the decisions you made in the last five years.” Paige decides to give her life with him a try.
When Leo takes her back to their apartment, all their friends jump out and yell surprise! Everyone is super happy to see Paige, but she is totally overwhelmed and runs to the bedroom. Leo sends everyone home, but Paige is furious that he would be so insensitive to how overwhelming it was for her simply to come home to a strange apartment with a strange man. She tells him to get out of the room.
The next morning, Paige wakes up and is shocked to see she has a tattoo on her back. Leo also wakes and absentmindedly comes into the bedroom naked. Paige shrieks, but laughs. When she comes out to the kitchen, Leo has made her a nice breakfast to apologize. Paige takes a bite of bacon, and Leo says, “Oh, that’s actually for me, you don’t eat meat.”
Paige asks what Leo does, and he explains that he runs a recording studio. She asks what she does, and Leo offers to show her the art studio, but she’s not ready yet. She tells Leo just to go about his day as usual, and as soon as he leaves she eats the bacon.
Leo heads over to the recording studio, where his partner Lily tells him things are going to crap without him.
Back at home, Paige is looking at all the records and books on the shelf. She finds a DVD with a note that says “More evidence”. It is the wedding DVD. She watches as her former self reads her vows to Leo. Leo reads his in return: “I vow to love you in all your forms, to always remember that this is a once in a lifetime love. No matter what challenges may come our way, I’ll always find my way back to you.”
Paige goes out to explore their neighborhood, and heads to Café Mnemonic where the barista asks if she wants the usual. Meanwhile, Leo arrives home with flowers and sees that Paige has forgotten her phone. He heads out to look for her, and indeed, when Paige exits Café Mnemonic she is totally lost. She uses a store phone to call her mom.
When Paige comes home hours later, Leo is waiting frantic. Paige is dressed in chic preppy clothes that her mom bought while they were out. Paige says that her parents have invited them for dinner.
Paige and Leo drive to her parents’ house in fancy suburban Lake Forrest. Paige is excited to see all the streets and houses she remembers. They sit down to dinner with her sister Gwen, who has just gotten engaged. Paige’s mother has made Paige’s “favorite dinner” filet mignon. Paige’s dad asks about Leo’s family, who are all dead. They ask about Leo’s job, and he explains his passion for music, but they all just stare at him.
After dinner, they head out to meet some of Paige’s old friends. Paige notices her old friend Diana sitting at a nearby table, but Gwen steers Paige away. Paige is thrilled to see her old friends, and even more happy to see her ex-fiancée Jeremy (Scott Speedman). She obviously still has feelings for him, and she totally ignores Leo.
The next day, Leo complains to Lily that Paige was like a totally different person, some sweater-set sorority girl. Lily says that Leo needs to use the things Paige likes to connect with her, like when Leo used to tickle her to cheer her up.
Meanwhile, Paige takes the train to visit Jeremy at his office. She asks him what happened to their relationship. Jeremy says that Paige totally changed and dumped him out of nowhere. He couldn’t wait around forever, so he started dating their mutual friend Rose. Paige hugs Jeremy, and it turns into a kiss. They both apologize, and Paige leaves.
At home, Paige is looking through old photos. She tells Leo she can’t believe she shut out her family for five years. She tries to make a timeline with the photos to pinpoint the last moment she remembers. She becomes frustrated, and Leo tries to tickle her to cheer her up. Paige hates it, and Leo leaves the room.
The next morning, Paige tells Leo she is ready to see her studio. Leo shows her all her sculptures and the piece she was working on. He hands her a tool and encourages her to take a few strokes. He turns on the music she used to listen to, and Paige says, “Turn it down.” Leo says, “You used to listen to it so much louder,” and Paige screams “Shut it off! I have a headache!” Leo says, “I’m trying to help you, but I’m not your punching bag. We don’t speak to each other like this.”
The next day when Leo gets home from work, Paige is packing a bag. Her dad has come to take her home so she can help Gwen with the wedding plans. Paige promises to return after the wedding.
Cut to Paige at the hospital. The doctor asks how she feels, and Paige says she feels fine, but she hasn’t recovered any memories. The doctor asks if Paige might be blocking the memories because she is afraid of the different life she was leading?
Meanwhile, at the studio, Lily is pissed at Leo because he keeps taking so much time off work. Leo says that Paige is in Lake Forrest, and he needs to be with her. He says, “I need to make my wife fall in love with me again.”
Leo heads out to Lake Forrest for Gwen’s engagement party. Gwen’s fiancée admits that he is nervous about the wedding, and Gwen is angry until Leo smoothes the situation over. Leo sees Paige, who has highlighted her hair and completed her transition to full preppy mode. Leo asks Paige if she would love to read her favorite book again for the first time. He says their relationship could be like that they could live the best time in their life over again. He asks Paige to go out on a date with him. She sees Jeremy with Rose and hesitates, but finally agrees.
Leo takes Paige into the city for their date. He takes her to the place they first met, then to Café Mnemonic for waffles and truffles. They laugh and joke over dinner, then he drives her to the lake, where apparently they used to swim every month, no matter how cold it got. Paige agrees to give it a try even though it’s April, and they run into the water in their underwear. Afterward, they kiss, but it doesn’t go any further than that. Leo takes her back to Lake Forrest, and as she is about to go in the house he says, “I miss you so much. I love you.” Paige goes inside.
Gwen is waiting up for Paige. Gwen says, “I like Leo.” Paige says, “I do too,” but she starts to cry. She says “I don’t know who I am. I have a tattoo.”
Leo tells his friends, “The date was amazing, it was just like before. Everything I love is still in Paige.” His friends caution that Paige may not feel as strongly yet, but Leo doesn’t listen.
In Lake Forrest, Paige’s father announces that he got Paige accepted back to law school. Paige says, “I feel like I’m getting a free do-over in life.”
Cut to Gwen’s wedding. The family is laughing and posing for pictures, and Leo is totally left out. At the reception afterward, Paige dances and ignores Leo. Her father brings Leo a drink and says, “It’s time to let us take it from here. I know you’re drowning in debt because you had no health insurance. Divorce her.” Leo says, “You’re such a hypocrite. You never tried to put things right with Paige in all the time I knew her. You’re a coward.”
Inside the house, Jeremy approaches Leo and asks if Leo wants to be introduced around, because he looks creepy sitting on the couch. Leo says, “I’m waiting for Paige.” Jeremy says “Good luck with that.” Leo says, “You’re loving this aren’t you?” and Jeremy says, “A little.” Leo says, “Well guess what: Paige told me everything about you. How she would wake up at night asking herself, is this all there is?” Jeremy says, “Well did she also tell you how she threw herself at me the other day?” Leo says, “Paige outgrew you before, and she will again.” Jeremy says, “I’ll think about that while I’m in bed with your wife,” and Leo punches him.
Paige is pissed at Leo, and he confronts her about her feelings for Jeremy. Leo says, “It’s time to be realistic, your memory isn’t coming back. How do you look at the girl you love and tell yourself it’s time to walk away?”
Cut to Leo mournfully playing his guitar in the recording studio. He tells Lily about the first time Paige said “I love you.” He says, “That was two weeks after I met her. That’s how long it took before. She doesn’t love me now.”
Cut to Leo packing up the apartment, then to him meeting with a lawyer to sign the divorce papers that Paige has already signed.
Meanwhile in Lake Forrest, Paige is at the grocery store when she bumps into her old friend Diane. Diane looks really uncomfortable and says, “I just want to apologize to you. I want you to know that your father ended it with me as soon as your mother confronted him.” Paige is furious, and confronts her mom and sister for keeping the affair a secret from her. She says, “How could you use my accident to rewrite the past?” Apparently the affair is the reason she fell out with her family five years ago. Her mother says that she has forgiven Paige’s father since then.
When Leo gets home, he finds Paige waiting on his front step. She asks if he knew about the affair, and he admits that he did, but he didn’t want to drive her away from her family again.
Cut to Paige at law school. Instead of taking notes, she is sketching. Then she heads out to lunch with Jeremy. Jeremy says he broke up with Rose, but Paige is no longer interested. She says, “I need to see what it’s like to be without you.” Jeremy says that is exactly what she said the last time she broke up with him.
Then Paige meets up with her dad, and informs him that she is leaving law school again and getting an apartment in the city. Her dad says, “I don’t want to lose you again.” Paige says, “You won’t,” and they hug.
A montage follows of the seasons passing. Paige is painting a mural in the nursery with her pregnant sister Gwen. Leo is recording music. Paige is sculpting in a new studio. While looking through some old boxes, she finds her vows written on the Café Mnemonic menu. Leo’s voice says “Moments of impact send some particles closer than before, while others spin off where you never thought you’d find them.” It is winter again, and it’s snowing.
Leo heads over to Café Mnemonic, but it is closed because of the snow. As he stands outside the door, he sees that Paige has come to eat, as well. They smile at each other. Paige tells Leo she has moved back to the city and is attending the Art Institute again. She says, “My hands remember what my mind forgot.” Then she says, “Thank you. You accepted me for who I am, not what you wanted me to be.” Leo says, “I just want you to be happy.” Paige asks, “Isn’t there a Cuban place around here we used to like?” Leo says, “Are you starting to remember?” Paige says, “No, but I’ve been spending time with Lily. She tells me you’re not seeing anyone. Would you like to go to the Cuban place?” Leo says, “What about trying someplace new?” Paige says, “I’d like that.”
As they walk away through the snow, text appears on the screen that says “The couple that inspired this story are happily married with two children. She never regained her memory.” A photo is shown of the couple with their two beautiful blond children.