What drew you to this character?
She just felt so much like me. I like people, I like laughter, I like joy. Crazily, I’m known for playing someone who’s the opposite. [Khaleesi] never smiles.
Did you feel pressure to please the book’s fans?
I’ve made naive choices to take on roles that are beloved–Thrones, Terminator, Breakfast at Tiffany’s. For better or worse, I’ve worked really hard to please the fans. For the first time, with this one, I read it and was like, “I’ve got this. I know her.”
How do you handle criticism?
With Game of Thrones, I feel more pressure the bigger it gets. Every season, I’m like, “Don’t let this be the season I f-ck it up.” I’m reading and researching. I watch as many strong female leaders as I can. Season 1, I got obsessed with Cate Blanchett in Elizabeth. Then I decided to watch Tilda Swinton in everything she did. I follow current affairs to try to understand where power comes from. Trump’s a hoot for that–all that self-confidence. I’ll watch speeches by leaders in languages I don’t speak, and I see if I can understand what they’re saying just based on the delivery and try to emulate that.
You’re known as a prankster. Did you pull any on the set of Me Before You?
It all began with a Khaleesi bobblehead doll that I was given. I mislaid it and blamed Sam. Then I found it and planted it in his bag. He held it ransom, so I put a fart machine in his wheelchair. Then Sam stole all the furniture out of my room, so I put fish in his socks, because I couldn’t think of anything else to do.
This appears in the June 13, 2016 issue of TIME.