London Mayor Boris Johnson has admitted frittering away his student years "fooling around", but said he hoped his "embarrassing" antics with the Bullingdon Club drinking society could now be forgotten.
In a highly-personal interview with US broadcaster CNBC, Mr Johnson also recalled the freedom he and sister Rachel were permitted as children, describing how they caught cross-channel ferries together and sat in seedy cinemas while waiting for the train to their schools.
Mr Johnson described his childhood - partly spent on his grandfather's farm in Somerset - as a "pretty, uproarious, wonderful" upbringing with fewer restrictions than those imposed on modern-day children.
He told CNBC's Tania Bryer: "What is certainly true is that at a very young age we used to travel around and we would catch the ferry together - the glorified vomitorium of the Townsend Thoresen cross-channel ferry.
"I used to have to get it and we would go to Victoria Station and sit in the cartoon cinema with the paedophiles and waiting for the moment when we get the train to go to our school. I suppose in those days kids were allowed to do (more) things on their own than they are today and we had a great deal of fun."
Mr Johnson said that much of his childhood was spent "generally just mucking around" and admitted that little changed when he went up to Oxford University to read classics.
Reminded of his membership of the Bullingdon alongside Eton contemporary David Cameron, the Mayor told Ms Bryer: "I'm grateful to you for inviting me to revive these unhappy and embarrassing memories, but I think the blessed sponge of amnesia has wiped the slate.
"I owe the Oxford Union and the institutions there a huge amount. If I have a regret it's that I spent so much time fooling around frittering my time at Oxford when I should have focused more on serious stuff."
Asked about whether he might one day make a bid for the Conservative leadership, Mr Johnson said: "I was very lucky to be elected Mayor. I've got a massive amount to do; I've got a solemn duty, which I love and is my work, to get the Olympic legacy done.
"It's all-consuming and I think most sensible people who know enough about British politics know that I'm jolly lucky to be Mayor, let alone anything else and that's what I'm going to focus on."