Screen and stage star Sir Ian McKellen has revealed he is finding it increasingly difficult to remember his lines.
The Hobbit and X-Men actor, 76, said that he recently spent six months learning his dialogue for BBC period drama The Dresser.
He told Radio Times magazine: " We all have intimations, don't we, however old we are?
"B ut there are times a life when the memory really does get worse and the mind doesn't work as it should.
"And if you were to get to the stage where you couldn't remember anything at all, well, that would be very distressing. Fortunately, I'm not there yet."
But he told the magazine: "Lines get more difficult to learn. When I was a young man, people would ask how I remembered my lines, and I'd think 'That's the easy part!'
"Well, these days it's one of the problems. I do find myself thinking 'How am I going to remember it?'"
The Vicious actor spent eight months preparing for No Man's Land, the Harold Pinter play he starred in on Broadway in 2013.
"That was just memorising the lines, and that was working on it every day. But it's not yet that bad for me. I can do it. But for some of my friends... well, if you can't remember lines, you can't really act," he said.
Sir Ian, who plays an ageing Sherlock Holmes in new film Mr Holmes, said that he found it easier to remember Shakespeare's dialogue.
"If it's Shakespeare, God bless him, he'll have written them with a rhythm, and possibly a rhyme, and those things make it easier," he said.
"Age. As Bette Davis said, it's not for sissies. My version is that age should come with a health warning.
"All your life you bump into old people. First it's your grandparents, and then your parents turn into old people.
"But you never think you're going to be one of them. And I've just turned 76," he said.