Cameron Diaz, Gwyneth Paltrow, Ben Affleck and more! See the seemingly ageless A-listers celebrating 40th birthdays this year
Gwyneth Paltrow (September 27)
The GOOP founder admits her fears about 40 weren't exactly justified. "I was really worried about it, leading up to the day, but now I feel really happy and content with my life," the star (seen here in 1992) told reporters at an event Oct. 5. "I'm excited to move into the next phase. It's much more exciting than I thought it would be."