Her Teenage Diaries Were Never Meant to Be Seen. Now Millions Are Reading Them on TikTok (Exclusive)

Betsy Lerner has been writing since she was a kid, inspired by The Diary of a Young Girl by Anne Frank. Like Frank, she longed for a place where her thoughts and feelings could be understood.

Through high school and into her 20s, Lerner filled journals with reflections about her life. She still remembers her very first diary: beige with a tiny lock — chosen because it felt “more serious” than the typical pink ones.

“All my diaries through high school got stolen when my car was stolen, but I have a very strong visual memory of that first diary,” Lerner tells PEOPLE exclusively.

Lerner later earned a Master of Fine Arts in Poetry from Columbia University before shifting into publishing. Her journals, meanwhile, sat tucked away in a crawlspace — until she rediscovered them thanks to TikTok.

“I got really interested in TikTok because of BookTok,” says Lerner, now 65. “I wanted to see what it was all about — the influencers and why so many books were suddenly moving off shelves, especially during COVID.”

At first, she posted small literary thoughts without showing her face. But after a friend encouraged her to create something consistent, Lerner decided to share entries from her old diaries.

“The first one I did went viral, and that was all I needed to keep going,” she recalls.

Today, Lerner has more than 46,000 TikTok followers. She says the real reward is hearing from viewers who relate to her experiences.

“So many people said they connected with my diaries — about depression, loneliness, and figuring out who you are,” she says. “These are really big, common themes in your teens and twenties.”

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When it comes to deciding what to share, Lerner avoids the most painful entries. Instead, she focuses on moments that are relatable, funny or even a little surprising. Sometimes she’ll stumble across boys’ names she no longer recognizes.

“It blows my mind,” she says. “When you’re in your 20s, you think every relationship is the biggest deal of your life and you’ll never forget. But then I also remember certain things very vividly when I read the diary.”

That mix of clarity and distance has also shaped her work as a novelist. On Sept. 2, Lerner will release her newest book, Shred Sisters, which she says was influenced by the voice of her diaries.

In particular, the character Amy — a scientist — reflects some of the struggles Lerner once faced.

“I wanted to create a character who believed in facts and the empirical world, not just feelings and emotions, which rule a lot of your life in your 20s,” she explains. “She feels very neglected within her own family. She’s not me — but she embodies some of the things I struggled with.”

“One of the things about Amy is she has to learn from the mistakes she makes,” she adds. “That’s what propels the plot: is she going to figure out how to deal with all the things she doesn’t like about her life? My hope is that the ending feels hopeful — not tied up in a bow, but hopeful.”

Looking back, Lerner says she wishes she hadn’t been so hard on herself. “I’d tell my younger self to trust that you’ll figure things out,” she says.

It’s the same advice she now offers to anyone curious about keeping a journal. “Try to write a little every day,” she says. “It doesn’t have to be profound — it could be a list, a goal, even something you overheard. Once you get in the habit, it gets easier.”

Her own journals were often part diary, part scrapbook. “Sometimes I’d write dialogue I overheard, or a list of things I hated,” she says. “I also taped in ticket stubs, candy wrappers, notes from friends. Especially in the early diaries, those little visual things bring the memories back vividly. There are so many ways to capture your life.”

Shred Sisters goes on sale in paperback on Sept. 2 and is available now for preorder, wherever books are sold.