Reports that Jack Nicholson has retired from acting because his memory will no longer allow him to learn the lines have been dismissed by Maria Shriver. Other friends of the actor have reported that he’s reading scripts as usual: he hasn’t been in a film for three years, and he’s 76, so perhaps people have simply drawn the wrong conclusion. Having seen his last movie — the utterly forgettable How Do You Know — and forgotten it, I’d assumed he was just waiting for a better script before he put down his golf clubs again.

Audiences are often fascinated by actors’ ability to remember dialogue, and similarly intrigued by stories of them losing that ability: Michael Gambon was all over the papers last week, talking about his experience rehearsing The Habit of Art four years ago. The strain of trying to remember the hefty role of WH Auden was so great that Gambon was hospitalized and had to leave the production. He’s subsequently said his memory is so bad that it is dangerous for him to appear on stage, though he’s taking the risk for the National Theatre’s 50^th anniversary gala this autumn.

Remembering lines is incredibly difficult and most performers use tricks to help them memorise chunks of text: when I was a comic, I used to have to learn each new stand-up show while I was still touring its predecessor, which meant having well over two hours of script in my head at a time. I could (mostly) retain the two separate shows, but I found myself tripping over the steps to the stage every night: I became convinced that I was storing lines in the bit of my brain I’d previously used for negotiating my way past inanimate objects, into which I still walk, frequently, many years later.

And stand-up is vastly easier to remember than the lines of a play, partly because anything you’ve written yourself is easier to retain than other people’s writing, and partly because if you lose the thread, you can find your way back to it, or even appeal to the audience for help. But if it’s a play, and other actors are standing opposite you, waiting for a specific line as their cue, the pressure is really on.

No wonder some actors dodge the bullet and decide to use earpieces. Richard Dreyfuss caused a mild theatrical scandal in 2009 when he was seen wearing one in Complicit at the Old Vic. Again, it was a role with a lot of lines, and Dreyfuss in his youth was perhaps less careful of his long-term memory than he might now wish. Though some critics were appalled, I don’t see the problem with earpieces: I’d rather watch actors committed to their performance than see them panicking about line-retention.

As the Jack Nicholson story proves, actors can rarely rest on their laurels for long, before the rumour mill starts grinding. So maybe he should silence his critics by taking a meaty role on Broadway. The scripts might be better too.