GEOFF BENNETT: We are going to take a look at a digital museum dedicated to the idea of lost memories.

That is the result of one mans extraordinary efforts to return neglected or misplaced family mementos to their owners.

Special correspondent Christopher Booker reports from New York for our arts and culture series, Canvas.

CHRISTOPHER BOOKER: They can show everything from life's big moments to snapshots of the everyday, but these videos all share the same purpose, to find out just who these memories might belong to.

It is a task undertaken by a man who has been dubbed the Sherlock of TikTok.

DAVID GUTENMACHER, Museum of Lost Memories: Any photograph is my preferred priority.

But I am looking for anything that is technically a loss memory.

CHRISTOPHER BOOKER: For 27-year-old David Gutenmacher, his search often begins at a thrift store.

DAVID GUTENMACHER: It could be a home movie, a film reel, a VHS tape, a diary, letters, photo albums, and even memory cards that are stuck inside of cameras.

CHRISTOPHER BOOKER: During the early days of the pandemic in 2020, Gutenmacher was looking for a project when he stumbled upon a bucket full of old photos.

DAVID GUTENMACHER: Immediately, I thought that, if my family photographs were in there, I would want someone to flip over the back, read my family name on it, and then try to find me online.

So, I thought I might as well start doing that for other people.

COMPUTER VOICE: I found this strip of film at the thrift store in New York.

CHRISTOPHER BOOKER: So, he turned to social media and created what is the popular Museum of Lost Memories, a TikTok and Instagram account of the same name with more than a million followers combined.

DAVID GUTENMACHER: This is just some of the stuff that I have collected over the last two years.

CHRISTOPHER BOOKER: Gutenmacher, a social media manager for a health care company by day, brings his finds home to digitize and post to his accounts, hoping the social media platforms will help deliver the old videos, letters, pictures, and anything else he finds to their original owners.

Is there any commonality in the way of which these items have ended up in the places you have found them?

DAVID GUTENMACHER: Yes, I think most of the things that I find come from either a move or, after a family member passes away, a lot of the items get misplaced, boxed up, cleared out, and people don't really know what they are getting rid of.

CHRISTOPHER BOOKER: So far, only 10 percent of the materials has made its way back home.

But whether a return happens or not, he believes the effort is worth it.

DAVID GUTENMACHER: I just love it.

I think it's important.

I think it is extremely important.

I think that people deserve to have their memories back.

And I think that everyday life is important to be preserved.

CHRISTOPHER BOOKER: Just a month-and-a-half after starting the museum, Gutenmacher was able to make his first connection with this tape.

DAVID GUTENMACHER: Yes, I found this at a thrift store on Long Island.

The only clues we had to go off of were was that it said Africa.

But, right away, I realized it was a vacation from Africa.

So, they likely were not from there.

And then there was a shirt.

He was wearing a shirt that said Wesleyan University.

CHRISTOPHER BOOKER: That shirt was the key that helped identify Jono Marcus.

JONO MARCUS, Contacted by Gutenmacher: At first, being contacted, I did not think it was real.

I thought it was spam.

WOMAN: Coming along.

MAN: How you doing?

CHRISTOPHER BOOKER: In 1989, Marcus was 23 years old when he and his parents went on a safari to Kenya and Tanzania.

His mom brought a Sony mini D.V.

camcorder and captured this footage that would be found by Gutenmacher more than 30 years later.

WOMAN: I'm talking to you.

(LAUGHTER) JONO MARCUS: And we didn't really lose track of it like we lost it.

It just gets buried in the stuff.

And then my father died around seven years ago.

And when my mom moved house, it's a little cassette tape.

So, it just kind of got lost in there.

CHRISTOPHER BOOKER: Lost, until Gutenmacher's post went viral and a team of volunteers started chipping in to try to find out who this family was.

JONO MARCUS: This woman sent me a link, and I look at it in disbelief.

Like, sure enough, my mom and dad and I are trending on TikTok, which I didn't even know what that meant at the time.

So, it turns out that the video garnered so many comments that they -- TikTokers decided to do some Internet sleuthing and found me.

CHRISTOPHER BOOKER: Marcus, who is now 56 and lives in Bethesda, Maryland, ended up posting another video on TikTok, recreating parts of the original footage of with his wife and children.

He says these two videos which have been viewed more than 10 million times, struck a chord with people during the pandemic.

JONO MARCUS: I think it presented opportunities for people to finally just feel just themselves, let go, not be scared.

There have been a lot of TikTok posts that include videos of people crying when they see it.

And part of it is very -- it's a very simple kind of family on a safari.

And I think the ending with my father and then showing that he had passed, that just -- as an ending, that just really hit a lot of people.

CHRISTOPHER BOOKER: Since then, Gutenmacher has made several more connections, including with the Friedmans (ph), a Jewish family who were in Vienna in World War II and lost these photos taken in 1943.

With the help from his followers online, he was able to track down their relatives and later discovered they had likely fled to New York.

DAVID GUTENMACHER: And we were able to get in contact with that family and return those memories to them, which they had never seen before.

And it was just like -- it was the perfect story from start to finish of having just one or two clues, and then having so many people participate in trying to find that family, and then being able to find them in the end.

CHRISTOPHER BOOKER: With the viral success of his posts, people from all over the world have begun sending him materials, in hopes the museum can help find the original owners.

DAVID GUTENMACHER: I mean, people find things in Jordan, India, South America.

All over the world, people have sent in things that they find at their local thrift stores or even on the ground in the street.

CHRISTOPHER BOOKER: We watched the open one package from the United Kingdom.

DAVID GUTENMACHER: Oh, wow, look at this one.

Looks like a group of miners.

CHRISTOPHER BOOKER: It contains both a picture and a letter written in cursive addressed to "Jim, Ruth and the boys."

It begins with: "Birthdays keep coming along.

And it's nice to think that we're remembered."

DAVID GUTENMACHER: If I can leave anybody with any message, it's to preserve your own family history.

Scan your photographs.

Write down names on the back of them.

If you're young and your grandparents are still around, sit with them and ask them who's in what photograph, interview them, get their story down on video, convert VHS tapes, digitize your film reels.

All of this stuff is going away.

And the sooner you have it preserved, the better.

CHRISTOPHER BOOKER: Gutenmacher believes it's an effort that will pay off for generations to come.

For the "PBS NewsHour," I'm Christopher Booker in New York.

AMNA NAWAZ: I love that so much, rescuing memories.

(CROSSTALK) GEOFF BENNETT: Yes, absolutely.

AMNA NAWAZ: What a good mission.