Sir Ian McKellen struggles to remember his lines.

The award-winning actor, who's starred in a string of hit movies, including the 'X-Men' and 'Lord of the Rings' franchises, has revealed old age is making it increasingly tough to recall his words.

The 76-year-old star told the Radio Times magazine: ''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?'

''There are times in 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.''

Earlier this month, Sir Ian claimed having fun is the key to feeling young.

The acclaimed actor said he keeps his soul youthful by constantly challenging himself.

When asked how he keeps a youthful mind, Sir Ian said: ''Keep working, keep moving, keep exercising, keep thinking, keep enjoying yourself.

''Maybe you'll hold off the inevitable. You won't, of course! I don't think that I'm immortal like I did when I was younger. 'Die? Me?' Yes Darling, we're all going to die.''