For movie fans, one of the coolest things about the world of film is spotting the minor details, the small things, and the intricate little elements dropped into a movie. After all, these are the things that offer a sense of reward to an audience - and we all know that the majority of film fans love to be rewarded when watching a feature.
While many films are loud and proud in how they splash cameo after cameo appearance or nods and winks throughout their run time, there are other pictures that really make you work to see the fan-pleasing secrets and goodies that are hiding in plain sight.
Here, we're going to focus on movie appearances from big-name, A-list talents. Actually, to be specific, we're going to focus on the appearances of big-name stars that have completely passed you by.
Without you knowing it, some of the greatest performers in the history of modern-day cinema have been cheekily snuck into some of your favourite films.
So with that in mind, then, here are five such examples of times when one of Hollywood's biggest names has appeared in one of your favourite movies - and you were completely oblivious to it!
5. Nicole Kidman In Panic Room
Originally, Nicole Kidman was set for the leading role in David Fincher's Panic Room.
Set to play the Meg Altman role famously played by Jodie Foster, Kidman had to drop out of the project 18 days before filming was due to start. The reason for this was that the Australian actress had a recurring knee injury that she had suffered on the set of Moulin Rouge.
Despite Fincher's want to delay the shoot to accommodate Kidman, the studio vetoed that and instead Foster - who cancelled her gig as President of the Cannes Film Festival Jury in order to work with Fincher - was brought in to take on the Meg Altman role.
What you likely didn't know, though, is that Nicole Kidman still managed to make an appearance in the 2002 picture.
When Foster's Meg is losing her mind and is finally able to make a panicked phone call to her ex-husband Stephen, it's his new girlfriend that initially answers the phone. The voice of that girlfriend is none other than Nicole Kidman.