The only thing worse than awkward silence is small talk. That sentence in the new film Lucky sums up the mood of the character named Lucky, and of the film itself. Spare me the b.s., Lucky keeps telling his friends in the bar and diner of the tiny desert town where he lives his simple life while pondering the meaning of life and death, specifically his own imminent end as a 90-year-old.

This gem is about the everyday life a grumpy old atheist without a wife or kids — that seriously sums up the film. It is lean and tight, as screenwriters say. Surprisingly it is also deep and witty. In less than ninety minutes we learn a lot about this independent chain smoker who has outlived his friends: the story hews close to Stanton’s own life and beliefs. He walks a lot, drinks one glass of milk and two Bloody Marys a day, does “five yoga stretches every morning, 21 repeats each,” as he informs his skeptical doctor, and has a combination of good genes and dumb luck, the doctor thinks. Of course, film is really about the question whether that’s a good thing, when you believe, as Lucky does, that there is “absolutely nothing” after death.

Actor Harry Dean Stanton (Lucky) died at age 91 just two weeks before the film’s release. (Saying “passed away” would insult his final character, who, like Stanton himself, might reply: passed on to where?) Like his protagonist, Stanton was a stubborn smoker who lived a long, rich life with unusual charm and calm determination.

The movie starts with Lucky waking up and preparing for the day. The timer on the coffee maker permanently blinks “12:00” in red digital digits and the extreme focus on the timer that was never set makes clear it must have meaning. The story is filled with such tidbits: hints at significance. Most of them come back later — at his bar seat in the diner, on the couch when he works on the crossword while watching game shows (“my shows”). Lucky is an avid, though not very talented, puzzler. It seems the filmmakers ask the viewer to fill in the blanks; solve the puzzle of what’s going on in Lucky’s mind.

Here is a man without a god who seeks meaning. The running joke with the diner’s owner (Barry Shabaka Henley) is how they greet each other good-naturedly with the words “you’re nothing” — a favorite phrase of Stanton’s. A cloud of existentialist questions is hanging over the perfect little screenplay by Drago Sumonja and Logan Sparks, who was a close friend of Stanton’s. “Realism is a thing,” Lucky tells the bartender of the dive where he spends his evening. “Truth is a thing.” How he pulls it off I’m not sure, but somehow there’s nothing weird about a simple guy in cowboy boots walking into a bar and casually positing philosophical snippets to his drinking buddies.

It’s the same story in the scene where he accepts the invitation to a child’s birthday party from a Hispanic shop keeper Bibi (Bertila Damas). Like most in town, she feels sorry for Lucky and his loneliness, although he keeps reminding folks that being alone does not equal lonely. He stands out at the party, until he suddenly breaks out in song. The mariachi band joins him. Seeing the old man surrender to the music while the younger crowd admires his openness is a moving moment.

Stanton played a role in the new Twin Peaks. To me that TV series is both over-hyped and incomprehensible, but Stanton’s director there, David Lynch, plays a strong and important supporting role here as a troubled bar friend named Howard whose tortoise has escaped. Any pet lover will recognize the helpless grief of Howard as he reminisces about life without President Roosevelt, as the tortoise is called.

Lucky is surrounded by caring people who support him as he starts to sense and express his fears. In fact, the people around him help him grow and change in his final stage. At some point he finally does set that blinking timer. He accepts a tight hug from a sweet, concerned waitress called Loretta (Yvonne Huff). After threatening to fist-fight a mustachioed lawyer named Bobby (the underrated, consistently good Ron Livingston), the two have a friendly conversation. And when an old Marine Corps veteran (Tom Skerritt, handsome as ever) shows up at the diner, they dive into painful war memories together. It’s unforced and genuine, a brief and deeply American experience over pie and coffee in a diner somewhere.

His gruffness won’t keep these passersby away. The inquisitive way in which Bibi looks at him encapsulates what it means to care and listen. No one in this movie lets silence — awkward or not — be ruined by needless small talk.

The great film and TV actor John Carroll Lynch (Jackie) makes his equally great directing debut. He was a friend of Stanton’s and he wrote that “Harry Dean Stanton was an acting legend who insisted he didn’t act.” Lynch lovingly called this horse s–t, arguing that Stanton was actually a talented artist. But Lucky kind of proves the actor’s point. The film is plainly a tribute to the life of a man who first appeared on screen in 1954. His character keeps saying “you’re nothing,” but the movie shows Stanton was quite something.

Lucky (rated PG) opens Friday in New York and Los Angeles, followed by cities across the country in October.