Prince William chats to Newsround
Prince William has told a young cancer patient who interviewed him for CBBC Newsround that he aims to follow in his mother's footsteps by helping people.
The prince said he would support a new children's and teenage cancer centre at The Royal Marsden Hospital.
His mother, the late Diana, Princess of Wales, opened the current children's unit at the London hospital in 1993.
He also told Alice Marples, 10, of his one-time dream to be a policeman and how he got his "Harry Potter scar".
He said: "For a very long time my mother was involved with the Royal Marsden, and she had a very close connection with them. So I wanted to... follow in her footsteps, in that sense, and help," he told the young cancer patient.
Prince William did work experience at the children's unit in 2005 and was appointed president of the world-renowned hospital in 2007, a position formerly held by his mother.
He said: "Since doing that work experience I've learnt so much and met so many incredible people who have been unfortunate enough to, you know, have cancer - and most battle through it and have dealt with it in an incredibly inspirational way."
In answer to being asked what he would like to do if he were not a prince, he said: "A long time ago I wanted to be a policeman, when I was younger. I soon learned that probably wasn't a good idea."
He added: "At the moment I'm still doing some sort of helicopter flying, doing search and rescue... it's going very well.
"My instructors would probably say 'not so well', but I think it's going not too badly. I haven't managed to dent any of the aircraft, I haven't flown into any trees yet, so... it's going OK."
The prince also explained how a childhood golf accident left him with a "Harry Potter" scar.
Pointing to his forehead, he told Alice, of Burgess Hill, West Sussex: "That was for my Harry Potter scar, as I call it, just here. I call it that because it glows sometimes and some people notice it - other times they don't notice it at all."
He added: "But I got hit by a golf club when I was playing golf with a friend of mine.
"We were on a putting green and the next thing you know there was a seven-iron and it came out of nowhere and it hit me in the head.
"I was in hospital for that, but that was very minor compared to how many times you've been into hospital," he told Alice, who completed treatment for a tumour the previous week.
The interview comes days after the prince spoke at a reception for the Child Bereavement Charity of the "emptiness" he has felt on Mother's Day since the death of Diana, Princess of Wales, 12 years ago.
The full interview was broadcast on CBBC's Newsround on BBC One at 1705 GMT and will be available for 24 hours on the CBBC iPlayer.