History Main / TheseAreThingsManWasNotMeantToKnow

** The [[OurGodsAreDifferent Daedric Prince]] Hermaeus Mora has this trope within his sphere. Appropriately, he is also the only Daedric Prince to actually take the form of an EldritchAbomination, being an endless mass of tentacles and eyes. If there exists some bit of information in all of existence which he does not know, he will mercilessly acquire it by whatever means necessary. One in-game book describes a mage who tried to explore the realms of Oblivion. When he entered Hermaeus Mora's realm of Apocrypha, an endless library, he became enamored with the knowledge and never left. His voice still whispers to the writer, each time more and more alien. Further, according to Mora himself, he is/arose from knowledge that ''cannot exist'' (detritus concepts ejected from reality), rendering him not only the keeper of things man was not meant to know, but also making him something man ''cannot'' know.

** The entire ''Elder Scrolls Universe'' is considered a Thing That Should Not Be by many, with the most accepted theory being that Nirn, the "planet" of the games' setting, exists ''within the dream of a dead God.'' and yes, that's a Capital G god, who goes (or went, rather) by the name Lorkhan and whose ''decaying corpse'' makes up the [[AlienSky two moons]] over Nirn, though they tend to [[AFormYouAreComfortableWith look like ordinary planets]] to mortals who gaze up at them. The universe frequently experiences stability issues, often resulting in absolute ''breakages'' of the fabric of reality, known as "Dragon Breaks" where [[RealityIsOutToLunch reality steps outside for a cigarette break.]] The largest Dragon Break in history is known as the Middle Dawn, a period of...weirdness...so weird that even the Elder Scrolls, which themselves are Things That Should Not Be, either adamantly refuse to show what happened, or are ''absolutely stumped'' themselves. And the kicker is that this was set off by an ill-timed ritual and lasted for a total of ''1008'' years.

* Creator/IsaacAsimov:
** "{{Literature/Jokester}}": One man, with access to a [[MasterComputer super computer]] that can tell you anything if you know the right questions to ask, tries to discover the source of humor. He tries because he himself is a wonderful, though nonprofessional, comedian. Eventually it turns out the sense of humor was an alien experiment that would be halted as soon as anyone figured out that it was so, meaning [[NiceJobBreakingItHero he destroyed everyone's sense of humor]]. Plus, the aliens will now replace humor with something else. Who knows what?
** ''Literature/TheRestOfTheRobots'': In the introduction, Dr Asimov [[DiscussedTrope discusses]] how fiction often showed how trying to do something godlike (such as [[CreatingLife creating artificial life]]) was something hubristic that needed to be punished. His decision to have robots as tools was an attempt to defy that literary tradition.
* The protagonist of the Literature/{{Boojumverse}} story "The Wreck of the ''Charles Dexter Ward''" had previously dabbled in so-called forbidden science, unafraid of the consequences. After what she witnesses aboard the ''Charles Dexter Ward'', however, she decides that there are indeed certain areas of knowledge that man was never meant to meddle in.

* In the Creator/RobertAHeinlein short story ''Literature/ByHisBootstraps'', Bob Wilson sees one of the High Ones through a time viewer and almost loses his mind. It was the emotions the High One was feeling that caused his discomfort -- an overwhelming mixture of sadness, tragedy, grief and weariness.

* In Creator/RobertEHoward's ''Literature/ConanTheBarbarian'' story "Literature/AWitchShallBeBorn", Salome was turned out by the magician who raised her for not being sufficiently interested in this for its own sake.
-->"[[EvilSorcerer He]] drove me from him at last, saying that I was but a common witch in spite of his teachings, and not fit to command the mighty sorcery he would have taught me. He would have made me queen of the world and [[TheManBehindTheMan ruled the nations through me]], he said, but I was only a harlot of darkness. But what of it? I could never endure to seclude myself in a [[GoldMakesEverythingShiny golden]] tower, and spend the long hours staring into [[CrystalBall a crystal globe]], mumbling over incantations written on [[EyeOfNewt serpent's skin]] in the [[ThePowerOfBlood blood]] of [[VirginPower virgins]], poring over [[TomeOfEldritchLore musty volumes in forgotten languages]].\\
"He said I was but an earthly sprite, knowing naught of the deeper gulfs of cosmic sorcery. Well, this world contains [[AmbitionIsEvil all I desire]]--power, and pomp, and glittering pageantry, handsome men and soft women for [[SexSlave my paramours and my slaves]]."

* ''Literature/FireAndBlood:'' After the [[BodyHorror ludicrously horrific]] death of Princess Aerea, Septon Barth is ordered by King Jaehaerys I to never speak of it again. But he does write down about it, and states that while he possesses a general curiosity for things, in this case he figures he ''really'' doesn't want to know what caused it.

* ''Literature/TheHitchhikersGuideToTheGalaxy'':

* In the Creator/StephenKing short story "[[Literature/SkeletonCrew The Jaunt]]", teleportation is possible... but you'd better be unconscious when you do it. Anyone who goes through the process awake is driven completely insane and often dies. The man they tested it on managed to croak out "it's eternity in there" before dying. The story follows a family who is about to Jaunt to Mars. Their father tells them the history of the Jaunt process to kill the time before it is their turn, and when they go through, the young son holds his breath when the knockout gas is administered. A split second later, on the other side, his hair has gone completely white and the boy is quite mad, cackling that the Jaunt was much longer than anyone thinks before he rips his own eyes out.

* Played with in the ''[[Series/StarTrekTheNextGeneration ST:TNG]]'' novel ''Metamorphosis''. Watching Geordi's frustration at being unable to determine how an alien artifact works, Data suggests that they were not meant to know. After Geordi both rejects the idea and expresses disgust at Data of all people proposing a mystical explanation for something, Data explains that he means the artifact's creators may have designed it so that its inner workings could not be analyzed.

* ''Literature/TwentyThousandLeaguesUnderTheSea'': For the man of the 19th century, reaching the South Pole would be something man was not meant to achieve. In this novel, is lampshaded by Ned Land's opinion about the beauty of the South Pole’s icebergs (and those words are said just before the Nautilus is trapped by them and the crew is soon AlmostOutOfOxygen).
-->"it's a wonderful sight! Isn't it, Ned?"\\
"Oh damnation, yes!" Ned Land shot back. "It's superb! I'm furious that I have to admit it. Nobody has ever seen the like. [[{{Foreshadowing}} But this sight could cost us dearly]]. And in all honesty, ''I think we're looking at things God never intended for human eyes."''

--> '''Plankton:''' Mixed together with [[SecretIngredient the most important ingredient of all]]: four heaping pounds of freshly ground... ''(turns page, sees picture of himself) '''[[SapientEatSapient plankton]]!?'''''

* ''TabletopGame/{{GURPS IOU}}'' (Illuminati University) had a class in the Thaumaturgy department called "Things Men Were Not Meant to Know". There's also a class in "Men Things Were Not Meant to Know". Also, what the O in IOU stands for is a closely-guarded secret.

* [[http://comic.nodwick.com/?comic=2001-10-31 This]] ''ComicStrip/{{Nodwick}}'' strip had entirely too much fun with this, as quoted above. The Thing Man Was Not Meant To Know was discovered by She Who Must Be Obeyed and taken back to The Lands That Know No Name! ("Let me know if we stumble upon any proper nouns in all this mess"), but it turned out to be completely ineffective [[http://comic.nodwick.com/?comic=2001-11-15 (though apparently hilarious)]] when known by ''women...''

** "[[Recap/DoctorWhoS30E13JourneysEnd Journey's End]]": Donna gets caught in the Meta-Crisis which creates a ''[[CloningBlues second]]'' Doctor, who as a result becomes part-Human, while she gained a Time Lord mind. Unfortunately, it's a BrownNote, as over 900 years of Time Lord knowledge and experience shoved into her human brain almost kills her. To save her life, the Doctor has to permanently lock away ''all'' memory of him from her conscious mind.

** Also, learning that the Philosopher's Stone is created by [[spoiler:sacrificing mass numbers of human lives]] has driven many who have sought its power [[GoMadFromTheRevelation insane]]. In [[Anime/FullmetalAlchemist the 2003 anime version]], Scar's brother was one of the people thusly afflicted.

* ''VideoGame/{{Diablo}} II'' plays this one straight when Marius witnesses Diablo's transformation. He even says it "was not meant for mortal eyes."

* VideoGame/{{Persona 3}}:

* There exists... something... in ''VideoGame/StarControlII'' that causes horrible death to anyone who learns about it. [[UncertainDoom Maybe.]] This happened to [[spoiler:the Androsynth]], and to one scientist in your landing party, who read their science notes leading up to the event ([[GameplayAndStorySegregation except you don't lose a crew member]]). It is repeatedly stated by those in the know that ignorance is the best defense against this thing, as it cannot affect anyone who doesn't know about it. A race of EldritchAbomination aliens - the "fingers" of something else's "hand" - mysteriously appeared nearby around the same time. But they don't like it if you ask too much about what happened.
* ''Franchise/TheElderScrolls''

* "There are things I need of you. Things you may not understand, and may not wish to do, but please, do not make the same mistakes I did [...] Human nature sealed my downfall. My name is Philip. If we are lucky, then by the time you receive this, I will be dead. '''[[VideoGame/{{Penumbra}} If fate frowns, we all perish]]'''"
* In ''VideoGame/TheReconstruction'', Falitza allegedly destroyed her mind by "peering into the unknown". [[spoiler:[[SubvertedTrope Subverted]], though -- it's ObfuscatingInsanity. She was so sick of being "little miss perfect" that she staged the whole thing to get thrown into Sanctifel.]]
* In ''VideoGame/DarkSouls'', the final part of Big Hat Logan's storyline if you rescue him and learn all of his sorceries has [[spoiler:him going insane while trying to decipher and duplicate the spells of Seath the Scaleless, the dragon progenitor of sorcery]].

-->'''[[spoiler:Leviathan:''' [[AC:You have come too far...]]]]

* Halfway through VideoGame/PhantomDust, the protagonist and the leaders of a group called the Visions learn that [[spoiler: all of humanity that remains on Earth are nothing more than memory constructs created by the final human being before dying. Though the Protagonist, who was based on said human's best friend, had much more detail put into his creation, the others were rushed constructs who shatter and cease to exist upon witnessing the memory realizing their lives were essentially that of illusions.]]

[[folder:Web Comics]]
* In ''WebComic/MidnightsWar'', [[spoiler: Lord Dante, a vampire, feeds Dr. Wilson to the army of ghouls he created once he verifies they're under control.]] He feels guilty about it, but he cites this trope to his companion Arika, stating that vampires dance to no man's tune.

* In ''Literature/{{Revival}}'', the antagonist is obsessed with seeing what happens after death before he dies himself. It turns out you doon't want to do that, because a) you won't like it, and b) ''something'' will look back at you. Besides, the special electricity he uses to do this also isn't good for you at all because it's connected to that other side. He avoids using it on himself, sending someone else in his place, but it doesn't really help when you're going ''that'' far.

* ''Fanfic/AbraxasHrodvitnon'': In this Franchise/MonsterVerse fanfiction, [[Characters/AbraxasHrodvitnonTitansAndOtherCreatures Ghidorah]]'s biological capabilities even when reduced to a decapitated head basically make it this trope given flesh. Even just a head can induce BrownNote effects in humans who spend too much time around it and cause SanitySlippage, and humans experimenting on Ghidorah's tissue ends up creating [[TheAssimilator the Many]] whilst attempts to make fertility treatment derived from Ghidorah's tissue results in FetusTerrible.

* In ''LightNovel/NyarukoCrawlingWithLove'', Mahiro goes to visit the rooms Nyarko, Cuuko, and Hasuta have set up for themselves using a BiggerOnTheInside alien device. In Hasuta's room, he notices that all the corners are covered in putty; when he asks why, Hasuta says [[OOCIsSeriousBusiness very seriously]] that he's better off not knowing the answer.[[note]]Since ''Nyarko'' is based off of the Franchise/CthulhuMythos, presumably Hasuta is trying to proof his room against Literature/TheHoundsOfTindalos.[[/note]]

** The Mystic Eyes of Death Perception, a special ability which allows people to "see" death, in the form of lines across everything that can be cut through in order to instantly kill or break apart the object. However, not only is the human mind not meant to comprehend actually seeing the concept of death, the fact that the lines are literally ''everywhere'' constantly reminds the user of the fragility of everything that exists. The comprehension is enough that [[LightNovel/TheGardenOfSinners Shiki Ryougi]], who was already borderline psychopathic before she got the eyes, immediately tried clawing out her eyes when she realized just what her eyes were seeing. Meanwhile, [[VisualNovel/{{Tsukihime}} Shiki Tohno]] doesn't freak out nearly as badly initially, but continual use throughout the story degrades his health and strains his brain as his eyes get more powerful and start showing him the death of things he shouldn't normally be able to comprehend (like buildings and concepts).

* In ''Literature/ABrothersPrice'', the fact that male babies are often stillborn is somewhat treated like this, with women saying "Not in front of the menfolk" when someone tries to discuss it with men nearby. While it doesn't drive anyone crazy to know about it, hearing [[spoiler:a woman talk about how her stillborn son was perfect right down to his beautiful little blue toes, just, you know, dead]] is quite creepy.

* In the Creator/RobertAHeinlein short story ''Literature/ByHisBootstraps'', Bob Wilson sees one of the High Ones through a time viewer and almost loses his mind. It was the emotions the High One was feeling that caused his discomfort - an overwhelming mixture of sadness, tragedy, grief and weariness.

* Appropriately, ''[[TabletopGame/{{Munchkin}} Munchkin Cthulhu]]'' has a card called "Learn Things Man Was Not Meant to Know: Go Up a Level."
** ''Star Munchkin'' has the monster card "Thing Man Was Not Meant to Know". [[MarsNeedsWomen It wants to know women.]]

** Many, many years later (perhaps a thousand), as related in ''Literature/TimeEnoughForLove'', Lazarus Long goes back to the planet of those aliens and kills them. Apparently, the [[FanftasticRacism only reason he does so]] is to "prove" that HumanityIsSuperior.

* TooStrangeToShow -- Anything Man Was Not Meant to Describe.

** While agonizing, Fait tells Nadia and Jean that Nemo cannot surrender the knowledge contained in the Nautillus.

* ''Anime/NadiaTheSecretOFBlueWater'': When Jean ask questions about the launching date of the Nautillus, Electra replies that men want knowledge but that, sometimes, such thirst has to be reined in. In general, Nemo and his crew want to prevent mankind to learn too much about ancient Atlantean technology becore they're morally ready to use them, because he don't want humans to die in internecine wars, like the Atlanteans of old.

** While agonising, Fait tell Nadia and Jean Nemo cannot surrender the knowledge contained in the Nautillus.

* ''Anime/NadiaAndTheSecretOFBlueWater'': When Jean ask questions about the launching date of the Nautillus, Electra replies that men want knowledge but that, sometimes, such thirst has to be reined in. In general, Nemo and his crew want to prevent mankind to learn too much about ancient Atlantean technology becore they're morally ready to use them, because he don't want humans to die in internecine wars, like the Atlanteans of old.

* ''Wiki/SCPFoundation'':

* AlienGeometries -- Forms Man Was Not Meant To Comprehend.
* ArtifactOfDoom -- Things Man Was Not Meant To Use.
* BlackSpeech -- Speech Man Was Not Meant To Hear.
* BrownNote -- Stimuli Man Was Not Meant To Experience.
* EldritchAbomination -- Beings Man Was Not Meant To Meet.
* EldritchLocation -- Places Man Was Not Meant To Visit.
* PokeInTheThirdEye -- Beings Man Was Not Meant To Scry.
* TomeOfEldritchLore -- Books Man Was Not Meant To Read.
* YouCannotGraspTheTrueForm -- Things Man Was Not Meant To Comprehend Even After He Was Foolish Enough To Look At Them.