Daniel Day-Lewis revealed that his offspring had no idea their father was an Oscar-winning Hollywood actor and his eldest son thought he worked in construction.
The 'Lincoln' star - who has Ronan, 14, and Cashel, 10 with wife Rebecca Miller, and Gabriel, 17, from a previous relationship - has revealed his kids were clueless about their father's occupation as an Oscar-winning actor until recently.
Speaking to the Daily Mirror newspaper, he said: "They didn't even know what I was doing until a couple of years ago. In fact, my 14-year-old boy was asked what I did and he said, 'I think he's in construction'. That's how much they know!"
The 55-year-old star also admits he has an "old fashioned" parenting style, sharing the same values as his own mother and father before him.
He said: "I think I'm quite old fashioned. My parents believed in certain things, which I do too, and I want my children to also. But there's no guarantee they will."
Daniel - who is being tipped to win his third Best Actor Oscar for his portrayal as American president Abraham Lincoln - stayed in character throughout the entire film shoot and grew to love the historical figure, but says one downside to the role was having to wear make-up.
He explained: "I was in complete denial. It hadn't occurred to me I was going to need any make-up, so it came as a bit of a shock. I've tried to avoid using make-up over the years.
"I spent probably an hour and a half in the make-up chair every morning."