The tides of life see us add and acquire, collect and gather people, relationships, property and things. And as we age, we let — often reluctantly — those things and people fall away. As the tide goes back out we understand what Anne Morrow Lindergh meant when she wrote, “One cannot collect all the beautiful shells on the beach. One can only collect a few.”

Letting those “things” go — mementos, tchotchkes, collectibles — is often the hardest. This is a life lesson you pick up at estate sales, and helping aging friends or relatives thin out the material life that they’ve accumulated as they downsize their living quarters can be equally illuminating. What they have — photo albums, records, collectibles, sports trophies, etc. — had meaning to them. It can’t possibly be worth the same to someone else.

  “Nostalgia” is a somber, wistful dip into those waters, a movie about the value of memory and those memory jogging “things” that we gather around us might have. In the age of digital music and photography, when you’re one lost phone or wrecked computer away from losing a lifetime of photos, sounds and memories, Mark Pellington’s film grapples with the tangible things we gather around us, questions their actual value and mourn their loss.

The film meanders through assorted scenarios of letting go, letting the acquisitions of life fall away, introducing us to people coming to grips with what has enduring value to them and those around them, and what doesn’t. I can’t say it quite comes off. But as somebody helping an aging relative downsize, and from years of auctions and estate sales (the girlfriend’s side business is collectible resales), it spoke to me.

  John Ortiz plays an adjuster for an insurance company whose job has somewhat vague parameters. He’s not just the man who shows up when you’ve had a loss, photographing the things you lose in a fire. He also comes in and does that first assessment of what you have in your house that might be worth selling at auction.

His first visit is to an aged widower (Bruce Dern) living in a quiet old house filled so filled with cameras, radios, an out of date word processor, and books — some read, some he still expects to get around to reading. His granddaughter is arranging for the property and everything in it to be auctioned.

Daniel (Ortiz, of “Silver Linings Playbook”) is an old hand at his job, gently invading the 80something’s space, asking polite questions, making helpful suggestions and above all — listening.

“It never gets to me personally,” he says. “And it never gets old.” Each assessment is unique, each life and its connection to the things around it are fascinating.

Daniel’s next stop is more somber. Helen (Oscar winner Ellen Burstyn) is a widow whose house just burned down. She sits on the ruins with Daniel and recollects facing that dilemma we all fear but few face, that moment when you have to “decide what you take from a burning building.”

Would it be valuables, clothes, letters or photos? And think fast because what you’re doing is weighing exactly what in your life you can call “irreplaceable,” as the flames lick up the walls.

One thing she saved was an autographed baseball treasured by her late husband. But even that has a finite, firm price. She discovers that as she meets with a kindly sports memorabilia dealer (Jon Hamm, in his sweetest film role) and the focus of the narrative shifts.

Will (Hamm) has aged parents who are finally selling their old house, and he’s got to fly in to help his older sister Donna (the wonderful Catherine Keener) empty it out. Enlisting Donna’s teenage daughter (Annalise Basso) is a non-starter. The kid’s grown up in a world where photos and mementos are ephemeral. Nothing lasts so she, like many of her generation, look to collect “experiences.”

Tallie the teen realizes what Daniel the assessor knows to be a hard truth, that when we experience loss, “You’ll never replace your things or lives.” So gathering things to guard against that day is futile.

Big emotions are in short supply until the film’s act, and every performer who turns up — Nick Offerman, Joanna Going, Beth Grant, James Le Gros and Arye Gross play relatives and neighbors of those giving up the detritus of their lives — underplays every scene.

I can’t see anybody under the age of 30 getting much of anything out of “Nostalgia.” Pellington’s soft-spoken, meandering film feels autumnal in tone and in timing. It’s the sort of movie we might get more out of in that contemplative season of the year.

It demands attention. It requires a lot of life experience to connect to its themes and subject matter. It’s a movie for the old, and those dealing with the philosophical, taking-stock questions of life.

If that describes you,  sad as it sometimes feels, “Nostalgia” can be an exercise well worth doing.

MPAA Rating: R for some language

Cast: Ellen Burstyn, Jon Hamm, Catherine Keener, John Ortiz, Bruce Dern, Nick Offerman, Joanna Going, Arye Gross

Credits:Directed by Mark Pellington, script by Alex Ross Perry and Mark Pellington . A Bleecker St.  release.

Running time: 1:54