Difficult as it may seem to stand out in the company of Reese Witherspoon, Nicole Kidman, Laura Dern, and even Meryl Streep, Iain Armitage—at all of 10 years old—has already managed to do just that. On Sunday night, the actor will share the screen with all three—not to mention Zoë Kravitz and Shailene Woodley—in the season 2 premiere of Big Little Lies, reprising his role as the latter's young son, Ziggy Chapman. In a way, he's been instrumental to the show from the get-go: It's thanks to Ziggy that Woodley's character, Jane, hits it off with Madeline (Reese Witherspoon)—and makes an enemy out of Renata (Laura Dern)—in the first place.

He might only be 10, but at this point, Armitage is used to standing apart. In a profile earlier this year, Esquire described him as dressed "like a middle-aged off-duty billionaire." As for the observation that he "doesn’t seem capable of giving less than one-hundred percent at all times," it's something his résumé already readily attests. Armitage made his on-screen debut on an episode of Law & Order: SVU in 2017—the same year that he also ended up sharing the screen with Naomi Watts, Woody Harrelson, and Brie Larson in The Glass Castle, and with Robert Redford and Jane Fonda in Our Souls at Night. Oh, and he also landed the titular role of the CBS series Young Sheldon, a prequel to The Big Bang Theory that revisits Sheldon Cooper's (Jim Parsons) days as a child genius enrolled in high school. (It won him the Teen Choice Award for Breakout TV Star in 2018.)

Iain Armitage and Shailene Woodley in season 1 of HBO's Big Little Lies (2017).

HBO

But Armitage first found success even before all that. Thanks to his YouTube channel, Iain Loves Theatre, he earned the title of theater critic early on—one that the New York Times made official when he was all of eight years old. (At this point, it should come as no surprise that Armitage has grown up in show business; his father, Euan Morton, is also an actor, and his mother, Lee Armitage, is a theater producer who often accompanies him on set.) As for how seriously that reputation is taken in real life, Lin-Manuel Miranda, now apparently a family friend, didn't fail to notice Armitage's presence in the audience of a Hamilton preview when he was all of 6.

Those moments, along with many others, have been thoroughly documented on Armitage's Instagram—an account so robust that the 10-year-old has already achieved the milestone of claiming a handle that consists solely of his first name. (Rest assured, its bio reads, in part, "Account managed by adult.") Since his first post, with Rosie O'Donnell, in 2014, Armitage has accumulated more than 300,000 followers and seemingly endless selfies with his namesake, Ian McKellen. His gig as a red-carpet reporter at the Tony Awards has only made his celeb selfie collection—featuring Oprah Winfrey, Glenn Close, and Helen Mirren—even more extensive.

In between all that, Armitage also posts plenty of regular Instagram posts—or, at least, ones that would be regular if he weren't a preteen. The aforementioned "adult" running his account has taken care to document Armitage's forays to everywhere from a Yayoi Kusama infinity room to the subway, and Armitage's appreciation for pastimes like wearing fedoras and eating pizza.

Of course, there has also been no shortage of photos of Armitage with fellow cast members of Big Little Lies—particularly with his on-screen mom, who he danced up a storm with at the after-party for Big Little Lies's season 2 premiere. And more, no doubt, are soon to come.

Related: Nicole Kidman Says "A Lot of People" Told Her Not to Do a Second Season of Big Little Lies