The pleasures of "About Schmidt" are what might be called Midwestern pleasures: a sly sense of humor, sturdiness, self-discipline, solidarity. It might be the most Midwestern movie ever made.

Directed by Alexander Payne, who has essentially become the poet laureate of Omaha (as he showed in "Citizen Ruth" and "Election"), it meticulously examines a retired insurance executive with the inner life of a gnat as he comes to terms with retirement and mortality. Here's what happens: nothing much. Here's what doesn't happen: something much.

Payne is a comic miniaturist, who works in a small compass, as if through a magnifying glass with tweezers. What he imposes on the work is brilliant discipline and a complete toughness about not breaking character. He never goes for the cheap shot.

An anecdotal example: At Cannes, in an interview (not with me), Payne recalled the movie's biggest laugh. It came when Jack Nicholson, who plays Warren Schmidt, is sitting in a diner, interacting with a harried waitress. At one point, Nicholson improvised a line that reflected back to his famous diner contretemps with another waitress, in "Five Easy Pieces."

It was a brilliantly funny moment. In previews, everybody who saw it busted a gut and coughed up a lung in hilarity. It was the kind of vivid, perfect line that makes a movie a word-of-mouth hit.

Payne cut it.

He cut it, of course, because while it's something Jack Nicholson would say, it's not something Warren Schmidt would say. Warren Schmidt probably wouldn't know who Jack Nicholson was, since Jack was never big in Midwestern insurance circles.

There's not a lot of plot, just as -- have you noticed? -- in life. Plot is for movies that are about, uh, plot. You won't find much plot in the office of the actuarial expert of Woodmen of the World Insurance in downtown Omaha on the last day of his 30-year career with the company. He sits there, his face flaccid and unfocused. He's trying to feel something. He can't. It's not that he's dead inside, burned out, or anything glamorously existential like that. He just has natural inclinations toward silence over jabber, and a lifelong habit of repression. Maybe it's the biting weather, maybe it's those flat, featureless plains, but the upper Midwest in January is not a place where people sound off a lot. And Schmidt is Midwestern in the extreme: He's not a sophist, a glib ironist, a voluble chatter, a convincer. His life is narrow and defined; he is narrow and defined.

Except now he's lost his definition. Without those tables of far-off lives and deaths to chart, he has nothing. At home, with his wife, Helen (June Squibb, so right as a Midwestern insurance exec's wife, and so far from Lara Flynn Boyle you could not believe the same universe accommodates them both), the only thing he does is get in the way. He has nothing to do. His imagination remains inert, disengaged.

Then Helen dies (early in the movie; I'm not giving anything away) and after a bit of fiddling with, rather than dealing with, his grief, Warren decides to go on the road in a big RV. Zany adventures? Wacky characters? Fabulous coincidences? Orgies, fights, chases, trysts, betrayals?

It's the Midwest, okay?

With the nominal goal of attending his daughter's marriage to a not particularly outstanding fellow, he heads to Denver, only to find the roads clogged with . . . other Midwesterners.

Payne uses the ancient but effective device of the unreliable narrator to great effect. Warren, in a moment of trying to connect with the world, has begun to correspond with a pen pal, an African boy who would know nothing of American life. That's the joke: Warren knows nothing of American life, either, and we watch something -- a random transaction, a tiff, an encounter, a talk with his daughter -- and then we hear Warren's clueless, oblivious account of it in a letter, to mounting comic effect.

There are some further complications, which, as in life, aren't that consequential. He reaches Denver, he tries to get along, but really can't. He doesn't grow so much as adjust, if slightly and internally, to his daughter's new life and the smallness of his place in it. He sees Kathy Bates -- the mother of the groom -- naked, and so do we, and he recovers, and so do we. Life goes on.

Nicholson is fabulous. It's not the showy Jack of "Heeeeeeere's Johnny"; it's lumpish, repressed Warren, with no Jack, no famous eyebrows or wolfish leer in sight. It's just that old guy, what's-his-name -- oh yeah, Everyman -- struggling to make it through the night.

About Schmidt (124 minutes, at area theaters) is rated R for language and brief nudity.

Kathy Bates and Jack Nicholson don't smash any ankles or wield any axes, but that's okay.