Imagining your favourite movies with different titular character is a difficult thing to do.
These celebrities might've thought turning down these roles was the right move at the time but little did they know these career decisions would go on to haunt them forever.
These are the iconic movies celebs decided not to star in that would go on to become absolute classics.
Harrison Ford wasn't the first pick for Airforce One.
Harrison Ford as President James Marshall is considered one of the best portrayals of a US President on the big screen.
But as Ford revealed to The LA Times, the role wasn't always his.
"This was a script that Kevin Costner originally had and he gave it to me," the actor said.
"Kevin knew this was a big commercial movie and his schedule didn't allow him to do it. And he told [the producers] he would let it go only if I could do it.
"Now Kevin and I are not intimates. I've met him on a number of occasions and I like him very much. And I like him a lot more now because he really threw a winner my way."
Michael Keaton didn't understand Groundhog Day
There's plenty of people who still struggle to understand the premise behind the 1993 time warp hit and Michael Keaton was one of them.
It's difficult to imagine the wry weatherman Phil be played by anyone else other than Bill Murray but it was definitely on the cards.
Michael Keaton told Entertainment Weekly he turned down the lead in the 1993 comedy because he just "didn't get it."
Despite passing up the opportunity to star in easily one of the best comedies of all time, Keaton praised Murray's Groundhog Day performance. "it ended up being so great," he said.
"You can't do it better than Bill Murray did it."
Matthew Broderick could've played ruthless Walter White.
Bryan Cranston might've already had worldwide fame for his leading role in Malcolm In The Middle but it was his portrayal of high school teacher turned ruthless drug dealer Walter White in Breaking Bad that gave him the reputation as one of Hollywood's best actors.
Although rumours surfaced the Better off Dead star John Cusack turned down the lead, he dispelled these whisperings with a tweet back in 2013.
Didn't turn it down u crazy "@DJKnoxs: You made a mistake turning down the role of Walter White,Breaking Bad is the best T.V show ever"— John Cusack (@johncusack) September 29, 2013
The role was reportedly offered to Matthew Broderick as well, best known for his roles in Ferris Bueller's Day Off and The Producers.
Although his reason for turning it down is unknown, creator of the show Vince Gilligan admitted to the Hollywood Reporter he had to fight the network's 'suits' for Cranston to be the lead.
One of the show's executive's recalls, "We all still had the image of Bryan shaving his body in Malcolm in the Middle. We were like, 'Really? Isn't there anybody else?'"
The show is now considered one of the greatest series of all time and Cranston won three consecutive Emmy Awards for his role. Safe to say they made the right choice.
Matt Damon wasn't the first Jason Bourne
It appears 2000 was a big year for blockbuster spy movies and Brad Pitt was the one with plenty to choose from.
After Pitt's last minute exit from The Bourne Identity to instead star in Tony Scott's Spy Game, Damon was second on Universal's list.
The Good Will Hunting star and Oscar winner was on the rise in Hollywood and starring in the Bourne series cemented his role as an action star.
Spy Game still received a positive reception and was a moderate box office success.
Despite this, The Bourne Identity sparked an entire Bourne film series which has since grossed more than $2 billion AUD.
Michelle Pfeiffer could've won Jodie Foster's Oscar
Silence of the Lambs director Jonathan Demme was already close with his Married to the Mob star Michelle Pfeiffer so when the part of Clarice Starling was being cast, Pfeiffer was his first choice.
On playing the wiley, inexperienced FBI agent, Demme told The Daily Beast he "went right to Michelle ... I felt she could do anything. But it was way too dark for her so Michelle ran away from that part."
The movie went on to win five Academy Awards, including one for Jodie Foster's acting, was a major box office success and is still one of the best horror flicks of all time.
Pfieffer admitted she had a huge amount of regret for turning down the role saying "I don't have an innate commercial sense. I'm always wrong."
Molly Ringwald could've been Richard Gere's Pretty Woman
It's hard to imagine anyone other than Julia Roberts in that iconic red dress laughing hysterically at Richard Gere but it wasn't originally Roberts part.
The part was actually first offered to the actress that defined the 80s, Molly Ringwald.
The Breakfast Club star turned down the opportunity to play the prostitute Vivian Ward after seeing an early draft and labelling the script as "okay" in a 2012 Redditforum.
She added, "I gotta say, Julia Roberts is what makes that movie. It was her part. Every actor hopes for a part that lets them shine like that."
Despite Ringwald's acting career dwindling after she turned down the iconic role, Roberts' career on the other hand absolutely took off.
Starring in the 1990 romantic comedy set her on the path to become the world's highest paid actress for the whole of the 90s and the first half of the 2000s which included a $25 million cheque for her role in the 2003 film Mona Lisa Smile.
Tom Selleck could've been whip cracking Indiana Jones
Everyone's favourite archaeologist Indiana Jones could've been very different, or more specifically, could've sported a thick, bushy moustache.
It was a rumour for years that Tom Selleck was the first choice to play the hugely popular Indiana Jones but that he turned it down due scheduling conflicts with his detective show Magnum P.I.
Selleck cleared up these rumours when he was interviewed in 2014 for David Letterman's The Late Show.
"It is a true story ... The only thing that gets me mad is people saying I turned it down ... Spielberg offered me a screen test ... and I got the part."
Selleck admitted scheduling conflicts were the problem having already shot the pilot for Magnum "They held the offer for about a month but the longer they held the offer, the more the network [CBS] said no."
Selleck also told Letterman, Harrison Ford is "completely sick of this story."
The Indiana Jones franchise has grossed more than $2 billion to date with a fifth instalment due for release in 2019.
Ford, who has signed on for the newest film, will be 77 by the time of release.
Sean Connery could've been the wizard yelling 'you shall not pass'
There's no doubt Connery is kicking himself for turning down the role of Gandalf the wizard in Peter Jackson's Lord of the Rings series.
The Tolkien-adapted films remain one of the highest-grossing and most popular movie franchises of all time but Connery turned down the part because he didn't understand the script.
The producers tried a number of tactics to coax the James Bond star to take the role including offering a 15% stake of the box office earnings as well as $6 million per film but none of their schmoozing prevailed.
A 15% stake in the Lord of the Rings films would've earned the Scottish actor upwards of $500 million.
The fierce, sword-wielding Gandalf was eventually played by Sir Ian McKellen.