The 34-year-old `Unknown` actress said despite having had a successful career as a model and an actress she doesn`t feel she has learned enough about the world.
She said: "Getting older, I realised I didn`t know anything. I felt incredibly stupid. I`ve always been very self-righteous. I`ve always been like, `I speak three different languages, I`m so accomplished.` And everyone tells me, `You`re so pretty`, and then it was a big realisation that I don`t understand anything, that I feel like I`m not cultured enough, that I`m stupid sometimes.
"That`s my thing in my thirties. I want to work on `me` much more."
Diane said it was her desire to explore more of the world which prompted her to take roles such as in -Special Forces-, which gave her the opportunity to interview female kidnap victims in Gaza and Afghanistan to research her role as a journalist taken by the Taliban. The film was then shot in remote parts of Africa and the Himalayas.
Diane admits she was "horrible to everybody" during making the movie, but said the experience "really changed" her.
She added to The Independent newspaper: "I just thought it was fascinating on a personal level. How many times have I been at home, cooking dinner and the TV news is on, and you`re like, `Ugh! Turn this off!`
"You take for granted that you have access to information."