Emma Watson's interest in the 'Harry Potter' movies developed as the stories became ''darker''.
The 21-year-old actress - who has played leading lady Hermione Granger in the movie series for the last 10 years - began to enjoy the films, About A Boy wizard learning the world of magic based on the novels by J.K. Rowling, when it became more of a challenge for her to act in them.
She said: "I mean obviously I went from being a child to being an adult. As the material got darker, it got more challenging. When that started happening, I started taking more of an interest."
The British star - who has returned to education and turned to a career in fashion alongside her film work as she has grown older - also admits she will miss her character in the movie more than she will miss anything else.
She told the Los Angeles Times: "I'm just going to miss being her, living in her world."
Following her appearances in the 'Harry Potter' movies, Emma will next be seen in 'My Week with Marilyn', which is due out this year, and a film version of novel 'The Perks of Being a Wallflower'.