Prince William is frequently “caught off guard” by his grief for Queen Elizabeth.

The 40-year-old royal became first in line to the throne when his grandmother died on September 8 at the age of 96 after a record-breaking 70-year reign, and his father King Charles became the new monarch, but in his first public appearance since Her Late Majesty’s funeral, he said it is “comforting” that so many people care.

He said: “If you flip it on its head, it is always very comforting that so many people care. It makes it a lot better. There are certain moments that catch you out. You are prepared for all but certain moments catch you out.”

The Prince of Wales, who has been married to Catherine, Princess of Wales since 2011 and has three children with her: Prince George, nine, Princess Charlotte, seven, and four-year-old Prince Louis, added that it is the things he “doesn’t expect” that get to him the most, such as tributes to his late grandmother based on Paddington Bear after the late monarch appeared in a sketch with the children’s literary character for her Platinum Jubilee back in June

He said: “It is the things you don’t expect that get to you. Paddington is a a new addition but the corgis have been there for longer.”

The Prince – who was greeting volunteers and operational staff at Windsor Guildhall alongside his wife and spoke to members of the Crown Estate – added that it had been a “busy few days” since his grandmother’s funeral but thanked the workers for their efforts.

He added: “It’s been a busy few days but you guys have been doing long hours as well, so thank you so much.”