VIEW LARGER A photo illustration of items left behind in books at the Oakland Public Library in Oakland, Calif. All of these items share a connection: They were left behind in books returned to the Oakland Public Library.
Librarian Sharon McKellar collects the found artifacts and posts them on the library's website in a collection titled "Found in a Library Book."
VIEW LARGER Remember, I Love U McKellar was fascinated by the things she'd find at the library and the anonymous glimpses into people's lives they offered. She thought the public may be interested too, so nearly 10 years ago she began adding found items to the library's website.
"I had always collected little things I'd found in library books and I knew other people did that too," McKellar said. "So that was how it started. It was pretty simple, I was inspired by a magazine called Found Magazine."
Oakland librarians send McKellar the things they find, which she then scans and adds to the library's growing online collection.
The archive now includes more than 350 items of all sorts. There are yellowed photographs, snippets of homework, bus tickets, love notes and postcards among the collection.
VIEW LARGER Alisha Many of the items appear to come from children. In one note, a child praises "Borok Oboma" for his speeches and family devotion. In another, the writer Ana asks someone in Spanish to check "yes", "no" or "maybe" to say if the two are friends (none of the bubbles are checked.)
Some of McKellar's favorites appear to have been left behind on purpose.
"There's an entire annotated Matilda by Roald Dahl, where a young person put Post-it notes all through the book with just things that popped into their mind as they read it, like, 'Wow! I can't believe the teacher did this,'" she said.
Many of the items seem mysterious without context or origins, and for more than nine years no one ever reached out to claim one, McKellar said.
That changed last month, when Jamee Longacre was looking through some of the collection and a green sticky note caught her eye.
VIEW LARGER Constipation in Babies!! 
"I even jokingly leaned further in closer to my computer screen," Longacre said, trying to scrutinize it. She recognized the loopy letters of her own handwriting.
Longacre is from nearby Concord, California. She said she remembered writing the note, but couldn't recall the context or who it was given away to. She said she hadn't been to one of Oakland's libraries.
"I just kind of giggled to myself," Longacre said, when she realized the note was her own. She reached out to McKellar to claim it.
To McKellar, the project's fun lies in imagining an item's possible history and the person it belonged to.
"It lets us be a little bit nosy. In a very anonymous way, it's like reading people's secret diaries a little bit but without knowing who they are," or breaching anyone's trust, she said.
She said the library may someday hold a writing contest and ask people to submit short stories to go along with the found items.
Under McKellar's desk, she keeps a box of more found notes waiting to be added to the website. In between meetings, she'll often take out a note or photo or a drawing and examine it.
"I wonder if it was a precious object to somebody," McKellar said. "Does the person miss that item? Do they regret having lost it or were they careless with it because they actually didn't share those deep and profound feelings with the person who wrote [it]?" she wonders.
Then she'll scan the item and add it to the collection.
NPR's Vanessa Leroy contributed to the digital version of this story.
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