* CompletelyDifferentTitle: In Spanish, while the film was released in Spain under the closest translation possible (''El incidente'', "The Incident"), in Latin America it was released as ''El fin de los tiempos'' ("The End of Times").
* CreatorBacklash:
** Creator/MarkWahlberg has admitted that this is one of the worst films he has ever done.
--->"…Fucking ''trees'', man!"
** WebVideo/ChrisStuckmann once relayed an anecdote about when he attended a screening of ''Film/TheCabinInTheWoods'', which starred Creator/KristenConnolly, aka the friend of the knitting needle woman from the opening scene. When he asked about her experience on ''The Happening'', Stuckmann noted that Connolly's expression [[OhCrap turned sour]].
* CreatorChosenCasting: Creator/MNightShyamalan wrote the screenplay with Creator/MarkWahlberg in mind for the lead role.
* CreatorKiller: Creator/MNightShyamalan was already feeling it after ''Film/LadyInTheWater'' became his first bona fide failure since he became famous, but this film only made him that much more of a laughingstock. While the film was successful at the box office (unlike ''Lady in the Water''), Shyamalan briefly [[Film/TheLastAirbender left the]] [[Film/AfterEarth horror genre]] for a few years afterwards, so when he came back with ''Film/TheVisit'', he was able to market it on nostalgia for his earlier pictures and avoid the impact of ''The Happening'''s notoriety.
* DeliberateFlawRetcon: [[http://www.denofgeek.com/movies/26050/looking-back-at-m-night-shyamalans-the-happening This article]] argues that the film is actually a work of genius, the 'flaws' being deliberately worked in to subvert BMovie SciFiHorror tropes.
* MeaningfulReleaseDate: Given that it was ''supposed'' to be a chiller, it was released on [[ThirteenIsUnlucky Friday, June 13]], 2008.
* SimilarlyNamedWorks: There was another film called ''The Happening'' released in 1967, and most of the people who have seen it also find that one terrible.[[note]]Ironically, the 1967 ''Happening'' is a comedy with a reputation for being unfunny, the opposite reason that the 2008 ''Happening'' is considered bad.[[/note]] If it's remembered at all now, it's for being the screen debut of Creator/FayeDunaway, and for its hit title song by Music/TheSupremes.
* ThrowItIn: Creator/MarkWahlberg's line "Be scientific, douchebag" was improvised.
* VoiceOnlyCameo: Unlike most of his other cameos in his films, Creator/MNightShyamalan never appears in-person in this, but he provides the voice for the character of Joey, who is only heard from a phone
* WhatCouldHaveBeen: Creator/AmyAdams turned down the role of Alma.
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