The 37-year-old royal - who has children Prince George, five, Princess Charlotte, three, and 10-month-old Prince Louis with husband Prince William - has grown to appreciate how "important" the early years are for shaping children's futures.
Catherine met with a small group of professionals at a Mental Health in Education conference in London to discuss the impact of consistent mental health training for teachers and the challenges of implementing it.
She told the group: "When I first started out - and I've learned a lot in a short period of time working with organisations - I was very naive myself as a parent of really just how important particularly the early years are for children's futures.
"And how critical it is, everyone looking after children at a critical time, teachers, parents, and everyone who's caring for them, how important it is that we get it right.
"I didn't know what some of the issues that perhaps we take for granted here as experts know about, but it's being able to translate it to those who don't have the training in a way that the points come across clearly."