Hugh Grant says people assume he's wealthy because of the way he talks - and confesses he was a "pretentious" and "badly behaved" kid.
The 59-year-old Love Actually actor revealed that he used to impersonate his teachers, who often caught him acting out, including smoking in a park near his school, according to the Daily Mail UK.
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Grant said he went to a state primary school before going to Latymer Upper School in Hammersmith, London when it was a direct grant grammar school. The school now charges £6,945 (around $13,500 NZD) per term.
Grant's father was an eager painter and ran a carpet company as well as serving as an officer in the Seaforth Highlanders for eight years in both Germany and Malaya.
His mother taught Latin, French and music for more than 30 years in west London state schools.
Grant's parents both had military family backgrounds - grandfather Colonel James Murray Grant, DSO, was decorated for leadership and bravery at Saint-Valery-en-Caux during World War II.
London-born Grant spoke on BBC2's A Life on Screen, saying that people assumed he was rich because of the way he talks.
"But we were not rich, we weren't at all," said the father of three.
"I went to the state primary school in Chiswick, and then I did get into Latymer, which is now an extremely expensive school but was then was a thing called a direct grant school, so a local council could get you in if you weren't rich.
"They have a very good system now for helping people who wouldn't normally be able to afford to go there, and I'm all in with that."
The actor enjoyed doing impressions of his teachers, his favourite being his chemistry teacher Mr Hammond.
"He used to say, "Hugh Grant, you have got to be separated from Guy Bentley..." and yes, he caught me doing it once, and smoking in Furnivall Gardens," he recalled.
"Those are my children's favourite stories, "What else did you do Daddy, what other punishments did you get?" So yes, I was badly behaved and pretentious."
A genealogist Antony Adolph once said Grant's family history was "a colourful Anglo-Scottish tapestry of warriors, empire-builders and aristocracy", according to the Scotsman.
It's believed his ancestors include William Drummond, 4th Viscount Strathallan, James Stewart, John Murray, 1st Marquess of Atholl, Heneage Finch, 1st Earl of Nottingham, Sir Evan Nepean, and a sister of former Prime Minister Spencer Perceval.
Grant admitted last week in a Virgin Radio Breakfast Show with Chris Evans that he used to dislike the idea of marriage and kids.
But he did eventually marry, tying the knot with his long-term girlfriend Anna Eberstein in May last year, aged 57.
Eberstein, 40, had dated Grant for six years on and off before they married at a Chelsea registry office after the birth of their third child.
Grant was promoting his new film The Gentlemen along with co-star Matthew McConaughey on the show when he spoke about his wedding to TV producer Eberstein, admitting he'd "put off" marriage.
"It was a very small affair, that's all. It was very nice getting married.
"It was another thing I put off too many decades. Very nice. Very nice being married."
When show host Chris asked the star why he'd put it off for this long, Grant said he had simply been "wrong".
"Well, I was just plain wrong. I was wrong. And children, you know, I used to roll my eyes. People would say, oh Hugh you don't understand it, but they were right," he admitted.
"And that's why you played golf for so long," Chris said.
"Yes, of course. Sad, angry, old golfer," Grant said.