It isn't easy being a mother, even if you're someone who's blessed with numerous resources like Kate Middleton.

Middleton can find motherhood to be quite difficult at times, despite being the Duchess of Cambridge. The royal spoke about being a parent to 3-year-old Prince George and 1-year-old Princess Charlotte while introducing the new English documentary series Out of the Blue this week.

"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," Middleton explained, according to Us Weekly.

"Nothing can really prepare you for you the sheer overwhelming experience of what it means to become a mother," she continued. "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."

Unfortunately there is no real rule book for being the perfect mother, as Middleton noted, but it's all about doing the best with what you've got.

"For many mothers, myself included, this can, at times lead to lack of confidence and feelings of ignorance," she said. "Sadly, for some mothers, this experience can be made so much harder due to challenges with their own mental health."

The Out of the Blue documentary series delves into mental health in the early years of having a child. Middleton urged mothers to not feel down about themselves if they stumble or feel their confidence lacking.

"[It] should not be seen as a sign of weakness," she said. "Mothers take on an overwhelming responsibility of caring for their families. Their role is vital in providing unconditional love, care and support at home, particularly in the early years of a child's development. We therefore should do everything we can to support and value their hard work."

Tags: Kate Middleton Parenthood