A white feather drifts down out of an ordinary sky, lands at the feet of a man waiting for a bus, and he begins to talk. He is not a clever man — he tells you so himself, plainly, with a box of chocolates balanced on his knee — and over the next two hours he will meet three presidents, win a medal in a war he barely understands, captain a shrimp boat, start a running craze and lose the only person he ever loved, all without once raising his voice. Forrest Gump is built on a deceptively simple joke: hand the biggest moments of history to the man least equipped to read them, and watch what he keeps.

Tom Hanks plays him without a wink. There is no nudge to the audience, no secret cleverness hiding behind the slow Alabama vowels — just a man who means exactly what he says and does exactly what he is told, and somehow comes out decent on the far side of a brutal stretch of years. It is the kind of performance that looks easy and is nearly impossible: one false note of cuteness and the whole film curdles. Hanks never strikes it. He had taken the Academy Award the previous year for Philadelphia; he took it again for this, back to back, and you understand why the moment you watch him settle onto that bench and simply be.

Robert Zemeckis, the Back to the Future showman out of the Spielberg workshop, treats the film as a machine for feeling and never lets you see the gears. Industrial Light & Magic stitched Forrest seamlessly into archival footage so he could shake hands with Kennedy and moon Lyndon Johnson; they erased Gary Sinise’s legs frame by frame so Lieutenant Dan could lose them to Vietnam. Alan Silvestri’s score and a jukebox of period songs carry you decade to decade, and the feather that opens and closes the picture turns a special effect into a small thesis about chance. The craft is invisible exactly where it is doing the most work.

The shape is a picaresque sprint through the American back half of the century — desegregation at the schoolhouse door, the jungle of Vietnam, the ping-pong tables of Cold War diplomacy, Watergate glimpsed through a hotel window, the running years, the shrimp-boat fortune. Against all that motion stands Jenny, Robin Wright’s wounded counter-melody, drifting through the counterculture and paying its bills while Forrest holds still inside himself. Gary Sinise’s Lieutenant Dan, raging at a God and a fate that left him alive, gives the film its hardest and best dramatic spine.

It is also the film critics love to argue with, and the argument is worth having. Read it coldly and Forrest Gump can look like a fable that rewards the man who never questions anything and quietly punishes Jenny for the sin of wanting more than Alabama. The sentiment is laid on with a trowel; the politics, if you go looking, lean comfortable. None of that is untrue, and none of it quite lands a killing blow, because the picture is too well made and too tender to wave away. It earns its tears honestly even when it is playing the easy chord.

At the 1995 ceremony it won six Oscars — Best Picture, Director, Actor, Adapted Screenplay (Eric Roth, from Winston Groom’s novel), Visual Effects and Film Editing — beating Pulp Fiction and The Shawshank Redemption in a year people still relitigate. It grossed close to seven hundred million dollars and lodged a fistful of lines into the language for good. More than thirty years on you can roll your eyes at the box of chocolates and still feel the catch in your throat when Forrest talks to a gravestone. That contradiction is the movie. Few films have ever worked a crowd this shamelessly and this well.