She said: "People always say [I'm] really wise, but that scares me because sometimes I do things like this - I've got 'f**k' written on my fingers because I did drinking games with my friends last night.
"There's nothing wise about me.
"Sometimes I'm like, 'I've got so many people fooled.'"
But Maisie admitted she isn't as confident as she was when she began her career on Game of Thrones - on which she plays would-be assassin Arya Stark - at the age of just 12.
She told InStyle magazine: "I struggled with the hours when I was young. It was an adult show. I had to fit into a much bigger wheel.
"But being 12 I didn't find any of that daunting at all. The naivety of it... I look at all the conversations I used to strike up with actors like Sean [Bean] and people on set and I think, 'How did I used to do that?'
"I wasn't fazed by anything at all. And I do want to grasp some of that back because I have lost a bit of it. In this industry, it's easy to lose your confidence."