Sir David Attenborough has "false knees".

Sir David Attenborough

Sir David Attenborough

The 91-year-old naturalist has revealed he underwent surgery on the joints in his legs because he felt his limbs were "wearing out" 10 years ago, and he has praised medical science for giving him the opportunity to walk again.

When asked if he is fatalistic, the 'Planet Earth' narrator said: "Not necessarily. I've got false knees. I could have said 10 years ago that my knees were wearing out and accepted that. But hanks to medical science, I don't have to; I can have a false knee and accept the possibility of walking again, which I did."

David has admitted he is curious as to whether the afterlife exists, and although he has not stated whether he is afraid of passing away, he has revealed he is "scared" of being a burden and an "appalling encumbrance" on his children Robert and Susan - who he has with his ex-wife Jane Oriel - when he gets older.

Speaking about the one thing he wants to know before he passes, and if he is worried about his last day on earth, he said: "Whether there's an afterlife.

"I'm scared of being an appalling encumbrance on my children."

David has achieved a lot throughout his life, which has seen him gain 32 degrees from British universities, knighted in 1985, awarded an Order of Merit (OM), as well as the Commander of the Most Excellent Order of the British Empire (CBE), a Fellowship of the Royal Society (FRS) title, and many other accolades, but the one talent the nation's sweetheart wished he had was to be "more musical" and be able to play an instrument competently.

When asked about the skill he wished he had to Stylist magazine, he said: "I wish I was more musical. I play classical music on the piano every day but incompetently."