Un is the Loneliest Number
Amélie Poulain spends most of her life by herself. She's homeschooled by her chilly, distant mother. She lives in a small apartment alone. And while she works at the Two Windmills café, we never actually see her interact with any customers. What exactly does she do there?
Despite being alone so much, Amélie doesn't seem to be lonely. There's a difference. After her one friend, Blubber, a suicidal fish, is dumped in the river by her mother, Amélie creates a host of imaginary friends to keep her company. As she gets older, these friends don't appear as often (they're more likely to take the form of real-world objects), but she always has her active imagination to entertain herself with.
Because she spends so much time in her own head, she "notice[s] details that no one else sees." For example, she sometimes watches the faces of people watching a movie instead of watching the movie herself.
It's Amélie's sharp attention to detail that allows her to pinpoint what makes other people tick and to decide whether to help them—her lonely landlady, for example—or drive them crazy—the cruel grocer Collignon, for one. She envisions herself as a national hero, "Amélie Poulain, Godmother of Outcasts, Madonna of the Unloved," and she pictures her funeral as a televised event, like that of Princess Diana.
Amélie's deeds keep her occupied until the bumps into Nino at the photo booth. He seems like her other half—solitary and detail-oriented. It doesn't hurt that he's the cutest man in Montmartre. Obsessing over Nino and his photo album, Amélie starts to feel just a twinge of loneliness, now that she realizes she might be missing something if she stays by herself.
Amélie initially resists the urge to pursue Nino, both out of stubbornness and out of fear. Being alone for so long makes it difficult for her to interact with someone face to face. But her neighbor, Dufayel the painter, is even more of a shut-in than Amélie is, and he encourages her to pursue Nino. At first she mocks Dufayel, watching from her window as he eats dinner alone—even though she, too, is alone.
But eventually, Amélie pulls through, and she cooks up a scheme to meet Nino. She's "devising a stratagem," she would say, because Amélie is the rare person who can put passive-aggressiveness to positive use. However, Dufayel counters this interpretation of things: in his view, Amélie's is actually "cowardly." He believes the only way for Amélie to be with Nino is to tell him so to his face.
She's not ready for that. She devises her stratagem, and when it comes time to speak to him, she totally chickens out. He thinks she doesn't like him, but Gina, Amélie's coworker at the café, tells him otherwise. Nino visits Amélie at her apartment, but, still scared, she flat out ignores him—until a video message from Dufayel encourages her to go after him, because hey, she might never have the opportunity to again.
Amélie opens her door, prepared to run like Bridget Jones through the street, but Nino is right there waiting. As he's about to speak, she shushes him with a finger, pulls him inside, and kisses him tenderly—but, at first, cautiously—all over. That's Amélie's way. She finds a way to show Nino that she likes him without actually having to speak. It seems to work perfectly, because in the final scene, we see them riding on Nino's bike together, perhaps happily ever after.