!! The book provides examples of:
* AlternativeCharacterInterpretation: Not a full example as this is actually mused upon in the book, but the idea that the serum doesn't actually transform Jekyll into a different-looking evil man, it simply transforms him into a different-looking man, and it's the intoxication of being able to get away with any crime that leads him to act so evilly.
** Of course many adaptations, especially recent ones, decide to eschew the idea that it changes his looks at all and represent the changes purely by acting.
** In the book Jekyll pretty much admits that his motive for inventing the serum was nothing other than ForTheEvulz; he wants to be able to act immorally, but as Jekyll he'll always be worried about his respectable image (not really anything to do with conscience). As Hyde he doesn't have to worry, as the worst people think of him is that Hyde might be blackmailing him (and / or could be his BastardBastard son). And keep in mind that Jekyll chooses to keep turning into Hyde ''even after Hyde severely injured an innocent child.''
** Also of more modern debate, about a line Jekyll makes about Hyde growing. The word used there is "stature" which has more than one meaning. Does he mean Hyde would have grown to hulk like proportions or that he's just becoming healthier compared to the much skinnier dwarf form he starts off as compared to the more hearty stocked Jekyll?
** And then there's the implied Jekyll/Utterson context as seen below.
* CommonKnowledge: As noted in the intro, there are ''many'' common misconceptions about the novel.
* HarsherInHindsight: Hyde's crimes were heinous enough, but soon after the book was published, the Jack the Ripper murders took place. Even worse, one of the suspects was an actor who ''played'' Jekyll and Hyde onstage; his performance was so convincing that people began to believe it wasn't an act.
* HoYay: Too easy to read some Utterson/Jekyll into the former's concern for the latter.
** His fears that Hyde was Jekyll's lover, and was using that to blackmail him.
*** Homosexual undertones were read into the book early on, and a few of Stevenson's gay friends chided him for possibly bringing them to light at all. The recent passing of homosexual legislation up north meant that closeted homosexuality wasn't just a hot-button issue at the time, but that Stevenson could possibly have had it on the mind while writing. A closer look at the edits from the second manuscript seems to support this theory, as Utterson himself starts to read a little bit more into Jekyll and Hyde's perceived relationship. Then again, this was a time when two men could have a completely platonic [[RomanticTwoGirlFriendship Romantic Two-Man Friendship]] and not be chided for it (again, because the idea of two men having sex with each other was just too absurd for Victorian sensibilities).
*** A short story by Creator/KimNewman, "Further Developments in the Strange Case of Dr. Jekyll and Mr. Hyde", riffs on this; [[spoiler: Essentially, Hyde is a separate person. And he's Jekyll's lover.]]
* ItWasHisSled: The original story is a mystery about what connection the upstanding Jekyll could have to the shady Hdye. Pretty much everyone nowadays already knows the answer (which was a TwistEnding when the book was published)- Jekyll and Hyde are one and the same, the result of Jekyll taking a potion that split him into two selves, one normal and one totally evil. Often enough, the twist is the ''[[AllThereIsToKnowAboutTheCryingGame only]]'' thing they know about the story.
* JerkAssWoobie: Jekyll, [[AlternateCharacterInterpretation if you believe he truly had good intentions of course.]]
* MainstreamObscurity: Just ask a member of the general public to give you even a vague summary of the plot! As mentioned above, most people ''don't even know'' that the dual identity was originally a TwistEnding, and it is not uncommon to see [[Film/VanHelsing parodies]] [[Comicbook/TheLeagueOfExtraordinaryGentlemen of it]] where Hyde is literally an ogre monster- rather than simply an evil (but not even particularly ugly) man. To be fair, Hyde is described in the book as a misshapen dwarf so ugly he inspires hatred in people without them even understanding why (possibly an uncanny valley effect due to looking somewhat inhuman).
** A lot of people will assume the two girlfriends are part of the book's plot as well; they were introduced in the 1920 silent film (and if you ''really'' wanna go back, the very first basis for a lover was in the stage play version) and added to many subsequent versions.
* MisaimedFandom: Many people will use the idea of being a "Jekyll and Hyde" as an excuse for either their own bad behaviour or that of their loved ones: "The real me (Jekyll) would never do such a thing, it was this alien force (Hyde) that took over my body and made me do it." This arguably inverts the moral of Stevenson's story, where Jekyll's refusal to take responsibility for Hyde's actions was a big part of what caused things to go badly.
* MoralEventHorizon: Clearly, when Hyde brutally murders Sir Danvers Carew for absolutely no reason, he has reached this point.
* UncannyValley: This is how the other characters describe Hyde and recognize that he's not quite right. They always describe him as looking "deformed" somehow, despite having no outwardly noticeable disfigurements. This is subtlety is lost on subsequent adaptations, mostly because it's hard to show on screen, and partly because EvilIsSexy sells better.
* WhatDoYouMeanItWasntMadeOnDrugs: Inverted. Stevenson wrote the first draft of the story in one-sitting during a speed binge.
!!The Noah Smith play provides examples of:
* MomentOfAwesome: [[spoiler:Helen and Cybel]] end up defeating Hyde by tricking him into [[spoiler:taking the serum as written, which includes a typo that would lead to near-instant death]].