Cameron Diaz thinks 'Knight and Day' helped her through her grief at losing her father.

The 37-year-old actress was left devastated when her dad Emilio died of pneumonia in April 2008 during filming of drama 'My Sister's Keeper' and admits took on the role opposite Tom Cruise because she was desperate to have some "fun" afterwards.

She explained: "I'd spent a year in grief with my family and I just wanted to have some fun and go on a great adventure.

"I wanted to spend some time just having a laugh without it being something heavy."

The blonde beauty admitted she always bases her movie choices on things she likes, rather than how they can help her career.

She added: "I've always made movies for my own pleasure. I've never made decisions based on any sort of trajectory for my career."

Cameron recently expressed her sadness at voicing her 'Shrek' character Princess Fiona for the fourth and final time.

She said: I'm going to miss Fiona a lot. She's become a part of me."