Eddie Redmayne is dishing on his new life as a dad.

The 34-year-old British star, who welcomed his 4-month-old daughter, Iris Mary, with wife Hannah Bagshawe this summer, admits nothing could have prepared him to become a dad to the adorable tot.

“I don’t think anything can prepare [you],” the Oscar winner told ET’s Lauren Zima at the Fantastic Beasts and Where to Find Them junket in New York City over the weekend. “The amazing thing is everything that everyone tells you beforehand -- which is all cliché -- is true. You’ve heard it all before and yet when you're experiencing it, it feels like the first time and you suddenly start telling everyone these things as if they're completely new and original thoughts. And they’re like, ‘Yeah that's the cliché.’”

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“But all the things [like] different parts of your heart opening … it's really extraordinary,” continued the proud dad, who married Bagshawe in 2014. “There's this amazing thing with children -- whenever you're having a bit of a tired moment or something, it's like she's always just one stop ahead of you, smiling you along. It’s great.”

While his wee girl’s smile never fails to brighten dark days, it’s her relentless enthusiasm for life that Redmayne says is one of his favorite things about being a parent.

“Waking up every morning and going in [her room] and she's so excited to see another day,” gushed the Theory of Everything star.

Redmayne plays Newt Scamander in Fantastic Beasts, the first of a five-installment prequel series to the blockbuster Harry Potter film franchise.

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He also said he’s thrilled to be a series of a film that his daughter can watch when she’s older.

“I feel like we grew up watching those films and getting to dive into that world every year or two. I used to find it so cozy,” he said. “It was like getting a hug every year or two from J.K. Rowling and I love the idea of another generation having something similar. Even though Fantastic Beasts is a different period, it's still the Harry Potter world. It's still got that same warmth and kindness.”

See a clip of Redmayne in Fantastic Beasts and Where to Find Them in the video below.