Ultimately, a movie will always be judged by what the audience sees on-screen. Whether this is by critic reviews or box-office success, movie-makers have to ensure that what they're putting in their final cut is the best movie possible.
And yet, sometimes, what happens off-screen is just as important as what happens on-screen.
All of the moments in this list, albeit unseen by audiences, must have happened within the confines of their movie's narrative. They weren't filmed, or even scripted, but in the world of their respective movies, they undoubtedly took place at one point or another.
There are moments that fit this description in cinema that had the potential to be utter spectacles, and to truly enhance a movie. These ones, however, fall at the other end of that spectrum, and would've been painfully awkward to watch.
They're still awkward to think about, mind you, and can certainly change how you see certain parts of these movies...
10. Paul Meets Agent Zoil - Paul
Simon Pegg and Nick Frost have been frequent collaborators and good friends for many years, with their most notable on-screen work together being Edgar Wright's Cornetto Trilogy.
But away from Shaun of the Dead, Hot Fuzz, and The World's End, there was Paul.
Paul took the English duo across the pond, and brought them together with a ridiculous supporting cast including Seth Rogen, Bill Hader, Kristen Wiig, and Sigourney Weaver. One of the key players in the movie was Agent Zoil, played by the ever-brilliant Jason Bateman.
Though Zoil was initially portrayed as the FBI Agent obsessed with recapturing Paul, it was later revealed that he was actually Paul's friend, and was trying to save him from 'the big guy'. At some stage then, this FBI Agent must have come across an alien, and instead of doing what he was supposed to do, what he would've been expected to do... he befriended him.
This might not even be so strange, since exactly the same thing happened when Graeme and Clive first met Paul. But at some point, Paul also introduced Zoil to his future wife. How does that conversation go?