“Why didn’t anyone ever tell me that I had a brother? Because it’d have been nice to know him for more than just the past six days.”

When Charlie Babbitt is outside in public spaces, he more often than not covers his eyes with dark Ray Bans, even when those around him are not wearing sunglasses. An hour-and-a-half into a drive from Los Angeles to Palm Springs with his girlfriend, Susanna, he hasn’t said a word — “could you possibly say 10 or 12 words before we get to the hotel?” she sarcastically asks. He is defensive when he replies, and keeps his gaze fixed almost exclusively on the road ahead, rarely shifting his attention toward her. When he gets news that his father has died, his voice doesn’t break; he is seemingly unaffected: “Sorry about the weekend, hon,” he says, flatly. Besides occasional flashes of anger, that’s as much vulnerability as she’ll get out of him as long as we see them together. After he learns that all that his father willed a $3 million fortune to an anonymous trust instead of to him, he stands sulking by the family pool, small in frame. Susanna stands on the other side of a physical wall, far away from him, and asks: “How did it go?” “I got what I expected,” he replies, staring off into the distance. She stares back at him, but he doesn’t acknowledge her concern. Charlie rarely opens up or communicates his emotions unless he is trying to get something from someone. Everything else — until the end of the film at least — is a missed opportunity for anyone trying to connect with him. He doesn’t let anyone in.

Raymond, Charlie’s brother, struggles to connect with others for a wholly different reason. An autistic savant, Raymond is chatty and often brilliant — but his eyes dart and wander, never making contact with anyone else’s gaze. He can memorize the phone book, but can’t carry a conversation. He can count 246 spilled toothpicks on the floor in an instant, but crippling nervous breakdowns prohibit him from riding in a car in the rain, standing next to a hot bath, or boarding an airplane.

In spite of all of Tom Cruise’s charisma, Charlie is not a traditionally likable protagonist — he is completely self-absorbed and never fully redeems himself from this; the exploitative trip to Vegas, which comes late in the story, is his lowest moment in a series of self-centered choices.

Even though Dustin Hoffman’s performance is captivating, and he and director Barry Levinson take great care to portray Raymond with a level of empathy and compassion rarely given to characters with any sort of mental illness in movies before, he is elusive to us. We know when he’s scared, and there are moments in which we get the sense that he might even be fleetingly happy. But we never really know what’s going on inside of his head.

Rain Man is ultimately compelling because it places these two people, who have difficulty connecting with others, together on a journey that requires them to communicate. Their outbursts and arguments provide viewers with humor and drama — and for the characters, they gain a quality lesson in patience and communication.

The plot of Rain Man is simple, but we are as invested as we are while watching it because it drops these characters in situations that test their weaknesses and vulnerabilities, and lets them both sink and swim.

Because Charlie is reserved, brash, and somewhat unlikable, the writers needed another character besides the elusive Raymond to bring out some level of vulnerability from him. Susanna, the most prominent character in the film besides the Babbitt brothers, weaves in and out of the story as that vehicle for Charlie’s exposition. Their conversations in the first act of Rain Man function to provide backstory and motivation for Charlie’s actions; we buy these conversations as authentic because of how guarded Charlie is. It makes sense that he never would’ve talked about his childhood with her until pressed, and the expository dialogue only feels noticeably forced when Charlie says, “when I was a kid and I got scared, the Rain Man would come and sing to me” out of the blue.

That particular line of dialogue is a set-up for a play-on-words payoff later in the film that doesn’t quite work, dramatically, because of how contrived this set-up feels. But not all of the thematic dialogue feels deliberately planted like this. Counter to that, Rain Man contains an excellent example of how to set up dialogue that then comes full circle in a surprising, emotionally resonant, too: “C-H-A-R-L-I-E. Main man,” is the sweetest, most poignant line in the movie because of how well it is set up in early scenes and gradually recalled.

Rain Man is character-driven, not plot-driven. Through their journey, Raymond and Charlie give us a story about empathy, intimacy, and connection. How the characters speak to one another is one part of that story. How they interact with one another — and how the actors playing those characters are blocked within each frame — is another.

The first time that Charlie pulls Raymond in close, it’s an act of aggression; he wants Raymond to stop embarrassing him at a diner, so he yanks his brother’s head close to his and whispers a warning to him. At the end of their journey, their heads touch together in gentle intimacy as Charlie tells his brother how much he appreciates him, and Raymond calls him his “main man.” In between those moments, the characters pull away from each other, then come back together in a dance of frustration and connection. By the end of the movie, neither character has dramatically changed… but through this dance, they both have grown.

The literal dancing scene in the high-roller suite in Vegas is the best example of this tension between connection and frustration, and how that is conveyed through not only dialogue but character blocking. High on the rush of winning more than $80,000 in the casino below, Charlie offers to teach Raymond how to dance. They slowly sway in front of floor-to-ceiling windows, their heads close together in a rare moment of vulnerability and intimacy. They face each other as they dance. But then Charlie goes in for a hug, Raymond freaks out, and their connection breaks. They split; Raymond crosses behind his brother and looks off frame left as Charlie looks off frame right.

They may not be good at connection. But for a moment, they dropped their guard, trusted each other, and tried. These attempts add up over time to generate empathy and love. There may be a few problematic moments along the way, but that is a beautiful lesson, executed with grace.