The belief after watching a film that it could be real life. Most well known cases are the matrix (the belief that we are all in a game) and inception (the belief that we are all dreaming and everything is inside the mind of the person believing this). Most cases are harmless fun for kids but can lead to a warped perception of real life (people thinking inception is real have killed themselves in the belief that they will wake up afterwards in the real world)
Robs gone mad after watchinginception. He keeps waking sleeping people up with a 'kick' to bring them back up one dream level & thinking he can act like an idiot cos hes dreaming!" "I know! Major case of filmception
When your watching a film of a film within a film and you dont know what layer of the film your in.
A good example of this would be Cloverfield or Suzhou River.
Flexception is when one "flexes" appearing or acting bigger than he/she really is, whether it would be financially, physically or mentally. For example, taking a selfie or picture next to a vehicle or property that is not yours. A "Flexception" is doing this (flexing) under certain circumstances such as being on vacation or somewhere at sometime no one can call you out on your bullshit. Example, a vacation in Vegas where you stayed at the holiday inn but posted pics of you checking into the Bellagio.
I really didn't want to take a selfie at the jewelry store with all this jewelry on, but I made a Flexception.