It is often said you should never go back. Trying to replicate your early glories can give off a whiff of desperation and leave your once-mighty reputation in tatters.

So it’s no surprise that Ewan McGregor is torn over whether to reprise his most famous role as Trainspotting’s gallus antihero Renton.

The author behind the story, Irvine Welsh, wrote a follow-up book Porno, set 10 years after the original, and director Danny Boyle has said a sequel would happen.

And McGregor, 39, admitted: "I don't like being the guy that's making it not happen, especially when all the other guys want to make it.

"But I wouldn't want to do a sequel to Trainspotting if it was just for the sake of it and, if I'm honest about it, I wasn't that blown away by the book."

McGregor has a tough call to make, so perhaps he should look back at history to help him decide.

Sean Connery, arguably Scotland’s greatest actor, was tempted twice to return to the role he came to hate: suave superspy James Bond.

Sir Sean may have been dazzled by the cash enough to sign up for Diamonds are Forever in 1971 and Never Say Never Again in 1982, but it didn’t do his career any harm. He went on to win an Oscar and solidify his place as a Hollywood legend.

Less successful was poor old Gregory. When news emerged that Bill Forsyth was planning a follow-up to football romcom Gregory’s Girl, Scotland gave out a collective cheer.

But John Gordon Sinclair, returning to the title role in Gregory's Two Girls, struggled to bring a dud script to life, and his and the film’s reputation suffered.

In the world of football, two Kennys have grabbed the headlines as returning heroes, with mixed results.

Scotland legend Kenny Dalglish blotted his copybook at Celtic by bringing in John Barnes as manager with disastrous results, but his recent return to Liverpool, where he shot to fame as a player and manager in the 1980s and 1990s, is proving more successful.

Current international star Kenny Miller has played for both sides of the Old Firm in his career, and his eventual return to Rangers was seen by many as a sell-out. He did manage to confound his critics to an extent, but was sold in the midst of his most successful season as the Ibrox club battled to balance the books.

With the Scottish elections looming, who could forget the Lazarus-like return of our current First Minister, Alex Salmond. He stood down from the SNP’s top job in 2000, only to return in 2004. Only time will tell if his recent successes as leader will continue come May.