The 33-year-old royal revealed in a sneak peek (via BBC) of an upcoming documentary that he has become more "emotional" since the birth of his two children – Prince George, 2, and Princess Charlotte, 8 months.
"I'm a lot more emotional than I used to be, weirdly," William told TV presenters Anthony McPartlin and Declan Donnelly (aka, Ant and Dec) in a preview of When Ant and Dec Met the Prince: 40 Years of the Prince's Trust, a new documentary focused on the Prince's Trust, a charity set up by Prince Charles.
"I never used to get too wound up or worried about things," he continued. "But now the smallest little things, you well up a little more, you get affected by the sort of things that happen around the world or whatever a lot more, I think, as a father.
"Just because you realize how precious life is and it puts it all in perspective. The idea of not being around to see your children grow up and stuff like that."
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In a preview from last weekend, William and his brother Prince Harry, 31, also joked about their 67-year-old father's more embarrassing antics. According to William, he got upset when his father started giggling when there was a production malfunction during a Christmas play the young royal was narrating when he was back in school.
"He couldn't stop laughing the whole way through the production," he said.
"Several times I'd stop ... I'd cast an eye across, like you know, a big death stare, and then I'd try and get back to my lines, it was terrible."
However, the brothers also said that Charles has given them "incredible" advice throughout their lives and that the Prince of Wales is "incredibly driven" when it comes to his public duty and charitable causes.
When Ant and Dec Met the Prince: 40 Years of the Prince's Trust will air in the UK on ITV on Monday at 9 p.m. (GMT).