On Simon Mayo and Mark Kermode’s movie show on Radio Five Live a week back, Harvey Weinstein, the producer of the new Nelson Mandela biopic, told the story of how the great man, visiting the Tribeca Film Centre shortly after his release from Robben Island, didn’t want to talk about politics; all he wanted to tell the audience of directors, producers and actors was how important the movies were that he and the other prisoners had been allowed to watch on Thursday nights.

Was I the only person who immediately thought of Preston Sturges’s great  1941 comedy “Sullivan’s Travels” ?

That’s the one where our hero (played by Joel McCrea) is a successful director tired of churning out mushy comedies with titles such as “Ants in your Pants of 1939” and dreams of doing a more realistic film to be called “O Brother, Where Art Thou?”  (Yes, that’s where that particular title first turned up).

He dresses up as a tramp and heads off to find out about real life.  The good news is that he meets the luscious Veronica Lake; the bad news is that he ends up in jail.  He eventually manages to escape and returns to Hollywood, but not before all the prisoners have been allowed to watch a Walt Disney cartoon.  Seeing the effect this has on his delighted fellow jail-birds he realises that he should carry on with what he does best.

(Preston Sturges was also reported as having felt a bit guilty about churning out comedies.  But when these include “The Lady Eve” (Barbara Stanwyck and Henry Fonda); “The Palm Beach Story” (Joel McCrea and Claudette Colbert) and “Hail the Conquering Hero” (Eddie Bracken and Ella Raines), who’s complaining?)