Nerds and geeks of all stripes may be able to rattle off random, detailed information about their preferred obsession of choice (see Trekkie, Rail Enthusiast, Polka Dork, Yaoi Fangirl, Camera Fiend) but when it comes to things outside of those areas of interest, or practical issues, works tend to portray them as being clueless and ignorant of the world around them. Common sense ain't so common, after all.
Often, geeky and dorky characters will be Super Gullible and overly trusting, lacking even the most basic of Street Smarts. This is sometimes used to justify why they are a Bully Magnet, a Butt-Monkey, or The Chew Toy: savvier and crueler characters like The Con or the Femme Fatale just can't help but take advantage of their naïveté. Other examples take "naive" in the more "ignorant" route and depict nerdy characters as having a myopic worldview, not knowing anything if it is outside of their Geek Reference Pool. A video game nerd, for example, may know how to change a tire only because doing so featured prominently in one of their favorite games.
Nerds and geeks that are highly academic or genuinely intelligent are not exempt either and this trope is often used to knock Insufferable Genius types down a peg, revealing that their vast academic knowledge and intelligence are useless outside of their area of expertise, show the limitations of simply reading and studying something, or reveal them as being Ignorant of Their Own Ignorance.
Another common variation of this trope combines it with the Nerds Are Virgins stereotype and portrays nerds and geeks as specifically ignorant and naive about anything related to love, sex, and romance. It's not just that they've never had sex or gone on a date; they won't even know how sex works or what constitutes a date or what to do when approached by a flirtatious potential suitor. Tell a geeky character a mild sexual innuendo and they will end up a flustered mess, that is, if they can even recognize the innuendo as such. Highly intelligent nerdy characters (who are frequently depicted as being Literal-Minded due to their logical and rational thinking) will have the most obvious of come-ons and sexual euphemisms go right over their head. Sometimes, these quick-witted problem solvers will try to do their own research, only to find gross exaggerations or misinformation that they treat as the gospel truth. These characters are most likely to wonder What Is This Thing You Call "Love"?, will often be Oblivious to Love should someone show interest in them, and if they end up falling in love themselves, will be Unknowingly in Love.
That said, this does not preclude any Accidental Pervert shenanigans and indeed nerdy characters may get hit with the Accidental Pervert stick more often than others because this trope helps absolve them of true lecherous intent.
A frequent trait of the Stereotypical Nerd. Compare the closely related Ditzy Genius, key difference here is that nerds, geeks, and dorks are not always smart, let alone geniuses. For the same reason, this can also be a trait of the Genius Ditz if they're presented as a nerd. The Celibate Eccentric Genius may also be proudly ignorant of love and romance. Contrast Nerds Are Pervs, in which nerdy characters are depicted as sex-obsessed, often with deviant preferences and lecherous instincts.
Can overlap with Virginity Makes You Stupid depending on just how naive and ignorant these nerds are depicted as being. A dorky character's naïveté may also be why others find them Endearingly Dorky and this is often the unspoken reason why a dorky or nerdy Clueless Chick-Magnet is so clueless.
- Hidoku Shinaide: Nemugasa is a Stereotypical Nerd and Scholarship Student who likes to study and do well in school. Because of his focus on academics, he has zero experience with dating or sex before Maya forces himself on him.
- March Comes in Like a Lion: Rei is mostly a No Social Skills-having Stereotypical Nerd who's singularly focused on shogi, so he doesn't understand any of the implications involved in him, a young teen boy, hanging out at a house entirely populated by young girls, nor why anyone freaks out about it.
- Metamorphosis: Despite her changing her nerdy appearance, former Stereotypical Nerd Saki's gullibleness and naivete regarding the ill-intentions others have towards her is part of what leads to her ending up in so many horrible situations. In the first chapter, she hangs out with a random guy who hits on her, trusting him even as he tells her he's drugging her all because he tells her he loves her just to sleep with her. Justified, in that Saki hasn't had any friends for her entire adolescence, so she has little idea how to navigate social situations and is desperate to make friends.
- Princess Jellyfish: Tsukimi is a Shrinking Violet, Stereotypical Nerd who is naive about much of the world (social interactions in particular) but has a near encyclopedic knowledge about jellyfish. Her naïveté extends to dating and romance, much to the frustration of Kuranosuke, the Wholesome Crossdresser who has fallen in love with her. Even when Kuranosuke tries to put the moves on Tsukimi, she remains fully oblivious. It doesn't help that when Kuranosuke crossdresses, Tsukimi doesn't even see him as a man, let alone a romantic prospect.
- School Rumble: The studious Hanai is a Badass Bookworm, able to go toe-to-toe with Dumb Muscle Harima in a fight. However, when it comes to interacting with women, he can be utterly naive and clueless. For example, when offering to give a girl who broke her glasses a ride home on his bike, he doesn't seem to think there's anything wrong with asking her how much she weighs.
- Harboured & Encompassed: Horatio, a high achieving Ph.D. student on scholarship, is uninterested in romance until Archie comes along. He's also oblivious to sexual innuendos and unable to recognize flirting. When Archie has a panic attack in the middle of a make-out session, it doesn't even occur to Horatio that this reaction might be due to past abuse.
- Total Command: Mei is still the ditzy, Gadgeteer Genius she is in My Hero Academia. Her naïveté regarding sex shows up after Momo confesses that she likes Izuku. Shocked by the confession, Izuku's overworked brain decides that he needs to shut down and he promptly faints face-first into Momo's chest. Mei stares at them and wonders if that's what sex is.
- Fanboys: The head of security at Skywalker Ranch tests the main characters on whether they are actually the Star Wars fans they appear to be with a quiz. While half the questions are about Star Wars lore, the other half are about their knowledge of sex and the woman's body. The fact that the only one able to answer the sexual questions correctly is The Lad-ette proves their geek-cred.
- A Sister's All You Need: Chihiro is an Otaku and a lot of the more perverted stuff that Nayu says to her goes right over her head. She also had no idea what a vibrator was when she came across one in Ashley's home and bought Ashley's lie that it was a massager until Haruto explained it to her.
- Bludgeoning Angel Dokuro-chan: Chieri Ono is a shy, sweet, smart girl who doesn't know how to ask out her crush and is very embarrassed and uncomfortable when asked to read out loud from a book about the reproductive system.
- Ponder Stibbons the Magitek geek was pretty unworldly in his earlier appearances, for instance in Soul Music, where Ridcully has to stop him explaining the way they can "trap" Music With Rocks In to CMOT Dibbler, because he thinks it's interesting, and doesn't realise that telling an Honest John that the magic music you're trying to stop can be copied and distributed is unlikely to help matters. Subverted in later books, where he's become pretty savvy about University politics, due to being the only person on the faculty who actually keeps things running.
- In Making Money, Hubert Turvey, who spends all his time in a cellar tinkering with the financial modelling system he invented, is a genius in economics and engineering, but is completely clueless when it comes to the cutthroat politics of his in-laws, despite this being a large part of what he's modelling. He's also uncomfortable talking to women. Moist von Lipwig describes him as "not used to things that don't come with a manual."
- The Big Bang Theory: Played a variety of ways over the years.
- In the first episode, Leonard, along with Sheldon, goes to confront Penny's ex-boyfriend about collecting her T.V. from him. Leonard is cheerfully optimistic that the ex will graciously hand over the television. Sheldon, who observes that Leonard is "thinking with his penis", is less so. Sheldon proves to be correct, as the encounter sees the both of them returning home without their pants.
- In a case of Characterization Marches On, Sheldon actually becomes less aware of sexuality and how it works over the course of the show until he begins a physical relationship with Amy. In the first episode, during a visit to a sperm bank, he says he's not sure he can do it, to which Leonard says he's "practically a master at it." Later seasons, however, suggest that Leonard, Penny, and the others had to buy him a book on the mechanics of sex, despite him saying in an earlier episode that he was familiar with the mechanics of the procedure.
- In one conversation, Sheldon offers to help Penny with a small business venture, then brags that he naturally knows about economics:
Sheldon: Penny, I'm a physicist. I have a working knowledge of the entire universe and everything it contains.
- In one episode, Sheldon, understanding that Penny's online gaming addiction comes from feeling unsuccessful and unattractive at a low point in her life, suggests that she might benefit from a sexual relationship. He then asks another man if he's in a sexual relationship, and if he's open to one. The man understandably believes that Sheldon is hitting on him, but seems game enough. Sheldon, of course, has no idea how his proposition sounded.
- In one episode Sheldon is trying to learn how to make friends, and looking for books on the subject. He is directed to the children's section by the store clerk. He strikes up a conversation with a girl there, unaware of how creepy it would look for a grown man to be talking to a child of no relation in public. Leonard quickly whisks Sheldon away, telling him to keep his head down to avoid any security cameras. His ignorance on this particular line is repeated in a later episode, when Raj, Howard, and Leonard are working on a project to get more women involved in the sciences, where Sheldon correctly points out that their targeting of women at the university level is too late for any effective results, and says that they need to target the elementary school age. He then attempts to look up "How to make twelve-year-old girls excited", to which the others quickly intervene before he can execute that particular search.
- CSI: NY: "Do or Die" concerns the murder of a popular senior in an upscale high school. She had enlisted the smartest guy in the class to help her study so she could get into her college of choice. The guy is clueless as to her motivation and falls for her, thinking instead that she asked because she liked him, too. He's also clueless that his female best friend is actually in love with him. It's revealed that she killed the victim out of jealousy.
- House of Anubis: Alfie is the resident geek, who's obsessed with things like aliens and zombies, and tends to hyper-fixate on those things to the point of annoying the rest of the house. He's also clueless about romance, as shown by his attempts to win Amber over, where he can't tell if the better gift would be "flowers" or "an adoption certificate for a baby vulture". Additionally, he tends to be a pretty big pushover who Jerome easily manipulates into everything from "getting embarrassed" to "becoming The Mole", naively trusting his "best friend" despite being repeatedly pranked and tricked. He does become savvier over time though, and by season 3, has not only won over three love interests with his kindness and talents but has become aware of Jerome's schemes and actively avoids falling for his "advice".
- Shadows over the South: Simon was noticeably apprehensive about changing into the VR system's synaptic bodysuit with Teen Genius Alissa watching during his first Seeking scene. Alissa, oblivious to why Simon didn't want to get half naked in front of her, instead surmises that it must be because that bodysuit was universally hated by Technocrats at the Symposium due to it being made from uncomfortably form-fitting Future Spandex. She then assures him that she personally overhauled the VR system and it no longer needed the suit.
- I Was a Teenage Exocolonist: As a demisexual, Nomi-Nomi, an anime nerd, is repulsed towards anything related to sex, but might consider it in the future if their partner makes them feel loved and comfortable with them first. In their epilogue, they try taking it slow in dating, but they're in no rush and are already happy with their friends.
- Dexter's Laboratory: Dexter may be a Child Prodigy but he also has a seriously limited grasp on what girls are like. He often laments about his sister Dee Dee's "cooties", treating them as if they were an infectious disease. One episode ("Tribe Called Girl") had him infiltrating Dee Dee and her friends' slumber party like he was studying wildlife.
- Jimmy Neutron: Boy Genius: Jimmy is a child prodigy who loves and excels at science...and still believes in cooties. (He outright admits in one episode that he thinks "girls are icky".) Carl, a Sickly Neurotic Geek, is just as clueless and also believes in cooties.
- Gus Griswald is the New Transfer Student who is meek, socially awkward, and on the receiving end of bullying at the start of the series. Often the other members of the crew have to explain to him the rules and rituals of school life and how to best navigate it. This allows Gus to also function as an Audience Surrogate and is justified by him being the Naïve Newcomer.
- Gretchen Grundler is a Child Prodigy and The Smart Guy of the crew, but in "The Girl Was Trouble," when she ventures through the school's "underworld" and makes deals with the jerks and bullies to get her Galileo computer back, she leaves a trail of clues linking her to their misdeeds. As Miss Lemon says, her smarts are "all book and no street."
- The Simpsons: "Homer Goes to College" features Homer inadvertently getting his nerdy tutors expelled when a prank goes wrong. Moments after they leave campus, they bump into Snake, who asks to see their wallets claiming he's the "wallet inspector". The trio gladly hand over their wallets without any hesitation.
Snake: Whoah! I can't believe that worked! (runs away)
- Total Drama Island: Beth is a Stereotypical Nerd with her Nerd Glasses, Braces of Orthodontic Overkill, shorter and rounder physique, and very high ponytail. She has No Social Skills and wants to make friends, which makes her naive and easily fooled, something the other competitors have no problem taking advantage of.
- The Venture Brothers: While both titular brothers are rather oblivious to how most things work in the real world due to their "Science Hero" upbringing, Dean is the sensitive nerd to Hank's Dumb Jock and comes across as far more ignorant about women and sex. For example, in the episode "Fallen Arches," before spending the day with the neighbor's similarly aged daughter, Rusty attempts to give Dean The Talk, but Dean is so confused by it that he ends up putting on a play for her. Lampshaded by the adults:
Brock: How did that go?
Rusty: He staged Lady Windermere's Fan...