"This could very easily be taken out of context, and I think it's funny now, but I remember looking in the mirror as a kid and it would be like for an hour at a time, and I'd be like: I'm just so beautiful. Everybody is so lucky that they get to look at me," the actress, 27, tells Marie Claire UK's October issue.
"And of course that changes as you get older, but I may have held on to that little-kid feeling that was me alone in my bathroom," she says.
The Emmy-nominated actress, who told Playboy that she was glad she didn't have the body of a Victoria's Secret model in March, credits her parents for her outlook.
Alexei Hay / Marie Claire
"My parents both have really healthy attitudes about their own bodies but also about the range of things that can be beautiful," Dunham, who regularly appears naked on Girls, says in the magazine's 25th anniversary issue.
"But they also just always made me feel pretty and cool and smart, even in the moments when I have known – and still know – that my body wasn't fitting into a traditional Hollywood idea of the female body," she says.