This may come as a shock, but Friday, July 24 is Mara Wilson‘s 33rd birthday! The actress was only a kid when she stepped into the spotlight, so it’s honestly pretty crazy that she’s a full-fledged adult now! Yep, at only 9 years old, the brunette beauty starred in the flick Matilda as the title character, and now — more than 20 years later — she’s completely transformed herself into one of Hollywood’s biggest stars!

It turns out, she’s not the only one. Yep, a bunch of celebrities that we grew up watching are all grown up themselves now, and boy, do they look different. Prepare to feel old, you guys, because we went ahead and rounded up some seriously shocking then-and-now photos of the most popular child stars, including Elle Fanning, Mary-Kate and Ashley Olsen, Macaulay Culkin, Abigail Breslin, Frankie Muniz, the cast of Harry Potter and more!

Scroll through our gallery to uncover 20 child stars who you won’t believe are adults now.

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