Labour leader Ed Miliband has revealed he was a "bit square" as a youth, eschewing drugs and under-age drinking.
In a GQ magazine interview with Piers Morgan, he said his greatest talent was being "good at the Rubik's Cube".
Asked if he had ever been in a fight, he said: "Well, I may have been hit a few times. I went to a tough school."
Mr Miliband, 41, added that he would not bow to pressure to marry his partner, Justine Thornton, with whom he has two children.
He also refused to "boast about my sexual prowess" when questioned about his romantic history.
This followed a GQ interview in 2008 in which Liberal Democrat leader Nick Clegg suggested he had slept with "no more than 30" women.
'Would have killed me'
Mr Miliband, who was was elected Labour leader last year and is the son of Marxist philosopher Ralph Miliband, grew up in north London.
He said he had not taken drugs while at Oxford University, saying: "I was a bit square."
Mr Miliband also said he had not been an under-age drinker because he was "too square".
Asked what he would do if he appeared on the ITV1 show Britain's Got Talent, the 41-year-old hesitated before saying: "I used to be good at the Rubik's Cube."
He has also been attacked for taking paternity leave shortly after winning the Labour leadership, but Mr Miliband said: "Justine would have killed me (if I hadn't taken the leave), and rightly."
On marriage, Mr Miliband said: "It's a good institution and part of having stable families, but there are also people in unmarried relationships with stable families. I don't think politicians should order people to get married."
He insisted he would eventually wed Ms Thornton, but added: "The more people challenge me on it from a political standpoint, the more resistant I will become.
"We'll get married because we want to get married and love each other very much, no other reason."