An origin story told entirely through arguments
The Social Network structures almost its entire narrative around two lawsuits, cutting between the founding of Facebook and the depositions in which everyone involved gives a slightly different, self-serving account of what actually happened. That structure is the film's real thesis: a platform built to define and quantify friendship was created by people who, by their own sworn testimony, could barely agree on what friendship meant between themselves. Aaron Sorkin's script moves at a clipped, overlapping pace that makes founding a global company sound exactly as petty and fast-moving as a college dorm-room grudge, because in this telling, it mostly was.
Jesse Eisenberg's Mark Zuckerberg is written and played with a specific, cold precision — never quite malicious, never quite sympathetic, always three steps ahead of the room in a way that reads less like genius and more like a permanent, exhausting defensiveness. The film's final image, him alone at a laptop, refreshing a friend request to the girlfriend who dumped him at the start of the movie, is the most quietly devastating gut punch in a script full of loud ones.
The film never claims to know exactly what happened. It only insists that whatever did happen, nobody walked away from it with more friends than they started with.
The one character the film actually mourns
Andrew Garfield's Eduardo Saverin is the film's emotional anchor precisely because he's the only major character who wanted something as simple as loyalty, and got diluted out of the company he co-founded for wanting it. His confrontation in the Facebook offices, watching his ownership stake evaporate on paper in real time, is staged with more raw hurt than anything involving the actual money at stake — a betrayal dressed up as a legal technicality.
Earns it. A founding myth told with the tone of a courtroom cross-examination, which turns out to be exactly the right register for a company that would go on to define, and monetize, the idea of being liked.