Henry Winkler, best known for bringing “The Fonz” to life on Happy Days, is sharing how he spent years battling an invisible challenge while at the height of his Hollywood career.

The beloved actor played his iconic role for 11 seasons, all while struggling with dyslexia—something he didn’t even know he had until adulthood. Winkler said he was finally diagnosed at 31, only after his stepson was tested in third grade.

“My stepson, who’s now 53, was diagnosed, and everything the doctors described about him sounded exactly like me,” Winkler revealed in an interview. “It was the moment I realized I wasn’t stupid. My brain was just wired differently.”

Growing up, Winkler said school was a painful experience. Teachers scolded him, classmates mocked him, and he was often punished for not performing well academically. The emotional scars lingered long after he became a television star.

Even during his rise in Hollywood, dyslexia made every script a challenge. Winkler admitted reading lines was nearly impossible, so he leaned heavily on memorization and improvisation. “I couldn’t read well, but once I had it down, I could memorize quickly. I’d walk into auditions and make adjustments on the fly. Producers would say, ‘That’s not how it’s written,’ and I’d tell them, ‘I’m giving you the essence of the character,’” he recalled.

The late diagnosis was both freeing and overwhelming. “It shifted my entire perspective in a single moment,” Winkler shared. “I finally understood why I struggled so much. But the shame, the doubt, the years of feeling less than—they take a toll. I had to completely rebuild my self-worth.”

For much of his life, Winkler said he had never managed to finish a book cover to cover. Today, that has changed in a big way. Not only does he read, but he has also co-authored more than 30 bestselling children’s books alongside writing partner Lin Oliver. Their hit series include Hank Zipzer and Here’s Hank, both of which feature a boy navigating the ups and downs of school with dyslexia. Winkler’s newest project, Detective Duck, aims to inspire early readers just starting their journey with books.

Lin and I believe humor is the doorway that opens kids up to reading,” Winkler explained. “And I want every child to know this: struggling to read has nothing to do with how smart you are or how vivid your imagination can be.”

Now in his late 70s, the Emmy-winning actor and author continues to use his platform to encourage kids who feel left behind in classrooms—reminding them that learning differently doesn’t mean learning less.