"Personally, becoming a mother has been such a rewarding and wonderful experience. However, at times it has also been a huge challenge — even for me who has support at home that most mothers do not," the duchess said at the film event. "Nothing can really prepare you for you the sheer overwhelming experience of what it means to become a mother. It is full of complex emotions of joy, exhaustion, love and worry, all mixed together. Your fundamental identity changes overnight. You go from thinking of yourself as primarily an individual to suddenly being a mother, first and foremost."