->'''Prince Zuko:''' I've spent years preparing for this encounter... training, meditating... you're just a child!\\
'''Aang:''' Well, [[NotSoDifferent you're]] [[InsultBackfire just a teenager.]]
-->-- ''WesternAnimation/AvatarTheLastAirbender''

Common theme running through initial seasons of shows featuring a KidHero. The young hero meets a series of [[NotNowKiddo dismissive]] characters who assume ineptness because (wait for it) -- "You're just a kid." The dismissive characters can be good or bad, but will meet their comeuppance by the end of the episode (or the season, if it's a multi-episode arc).

Requires a show built around the concept of a hero who is stronger or more competent than they appear.

Because the conceit of this trope wears thin after two or three years, it often quietly fades, only to reappear in another character.

When its the villain instead of the hero whose youth is being remarked on, you might be dealing with an EnfantTerrible, in which case you're in big trouble.

See also StayInTheKitchen, where a character is as "just a woman" or "just a girl". Frequently found in plots based around athletics, or the MachoDisasterExpedition.

Such a character may frequently be on the receiving end of NotNowKiddo.

Not to be confused with ''Just a Kid'', the Australian name for ''CaitlinsWay''.
----
!!Examples

[[foldercontrol]]

[[folder:Anime & Manga]]
* Nue of ''Manga/AirGear'' is the Thunder King, making him one of the top riders of the series, and is also one of the youngest of the Kings.
* The Girl part of ''GunslingerGirl'' means that this is the usual reaction to them, even from people who have heard of their existence. The gunslinger part means that said people die soon after making this mistake.
* Lampshaded by almost all the villains Gohan fights in one-on-one battle in ''Anime/DragonBallZ''. Goku also suffered from this in the ''Manga/DragonBall'' series and in ''Anime/DragonBallGT'', which annoyed him even more, as he was reaching his sixties and was one of the strongest beings in the universe.
** Subverted with gleeful enthusiasm in ''WebVideo/DragonBallZAbridged'' whenever they can get some footage to support it.
-->'''Gohan:''' I'm not going to back down. I might be younger than you, smaller than you, weaker than you, and much less experienced, [[BrickJoke but I learned more about peach farming than you... ]] [[ThisIsGonnaSuck I think this was a horrible decision.]]
-->'''Recoome:''' [[PreAssKickingOneLiner Recoome agrees.]]
* ''Manga/FullmetalAlchemist'': Lieutenant Ross and Sergeant Brosh lecture Ed and Al on how their youth means that they should give adults some more responsibility in the story. Of course, Ross is effectively shut down by Maes Hughes, who, GenreSavvy man that he is, knows who the main characters are.
** Ed takes it quite well (despite [[HotBlooded his temper]]).
* ''ThePrinceOfTennis'': Ryoma's rivals often comment derisively on him being just 12-to-13 years old and in his first year of junior high. And they end up losing to him soon.
* Notably averted in ''MagicalGirlLyricalNanoha'', where the Time-Space Administration Bureau will recruit anyone sufficiently skilled and responsible (or plot-important), regardless of age. No one magical ever looks down on, underestimates, or refuses to fight Nanoha or her peers because of their ages. Even her {{Muggle}} parents are [[ReasonableAuthorityFigure surprisingly understanding and permissive]].
* 17-year-old turned 7-year-old Shinichi Kudo in ''DetectiveConan'' finds this a serious problem as no-one will take his deductions seriously. Then again, he still makes the best of the situation by constantly exploiting his ability to be underestimated by the culprits.
** He's not immune to the trope in his teenage body either. In a recent chapter, police detective Satou confidently told her partner that the two "high school detectives" would get stuck and come running back to the police. She was immediately struck speechless when they arrived to announce that they had whittled down 50 cars to just three suspects.
* ''Anime/SaberRiderAndTheStarSheriffs'': Fireball is often the butt of jokes because he's 18 years old and his teammates are all over the age of twenty. 24-years-old Colt is the one who treats him like a child the most.
* Saying that cute GenkiGirl {{Ninja}} Misao of ''RurouniKenshin'' is "Just a kid" is a good way to get yourself kicked in the head.
* Both Firo and Luck from ''LightNovel/{{Baccano}}!'' have a history of dealing with this. Because he started in the upper ranks of TheMafia at an age no greater than [[ImprobableAge fifteen]] (and potentially as young as ''thirteen'') thanks to family connections, Luck spent much of his career [[NobleDemon building up a front more ruthless than he actually is]] to counter it. Meanwhile Firo, while attaining his position at a somewhat later age and solely through his own skill, [[OlderThanTheyLook looks quite a bit younger]] [[ReallySevenHundredYearsOld than he may be]] and tends to get written off as a brat because of it.
* The title character from ''KingOfBanditJing'' is also a victim of this; you'd think by now the bad guys would learn that the infamous "Bandit King" is no more than 16 years old.
** His age is somewhat debatable - in the manga, due to the art style, he looks ''younger'', at least in the [[ArtEvolution beginning]].
* Daisaku gets this a lot at the beginning of ''GiantRobo: The Day the Earth Stood Still'', especially from Tetsuoko, who is jealous of Daisaku's mature manner (for a kid) but also of the close bond he shares with Ginrei.
* ''GundamWing''. Noin is bitter at having been defeated by "just a kid". To which Wufei retorts "You saw I was a kid and you underestimated me."
** Of course, he 'just a woman'ed her.
* ''[[Anime/MobileSuitVictoryGundam Victory Gundam]]''. Usso gets this a lot, given that he's only 13. He's GenreSavvy enough to use this to his advantage several times, because he knows people will underestimate him, or hesitate to harm a kid in battle. Of course, some of his opponents get GenreSavvy right back and treat him as as much of a threat as any adult soldier.
* ''Lightnovel/FullMetalPanic'':
** Ssuke Sagara gets this from time to time. Especially noticeable in the arc where he had to cooperate with other soldiers to assassinate Gauron. None of them (except Gray) were willing to listen to his advice or input, because they were so insulted that Mithril would send a "kid" to help. They were proven wrong within an episode, and it ended ''very'' badly for them because of it. Plus they were really shocked when they found out that Ssuke was an Afghan guerrilla when he was eight. Prior to that, he supposedly was a highly trained KGB assassin. Now he's 16 and the only man at Mithril who can use the Lambda Driver.
** Talking about the Lambda Driver, episode 12 shows what happens if you think of Takuma as a harmless kid. Hint: it involves a 50-meter-tall mecha and Tokyo.
* Many warriors have this reaction to Thorfinn in ''VinlandSaga''. They mostly end up dead as a result.
* ''Manga/MahouSenseiNegima'':
** Asuna seems to have trouble seeing Negi as anything other the [[BigSisterInstinct sweet little brother she has to protect.]] Even after getting taken down in a few ''seconds'' by him in a sparring match, she still worries about him far too much.
** During the elimination round of the Mahora Fesival TournamentArc, most of the other fighters were treating [[TheHero Negi]], [[TheRival Kotaro]], and [[OldMaster Evangeline]] as silly little kids that seem to have lost their way. The jokes stopped the moment people more than twice their size started getting effortlessly knocked around.
*** Evangeline's opponent in the first round tried to avoid this by treating her as an equal and not to be underestimated; of course since Evangeline is one of the strongest characters in the setting even while depowered, she still took him down in a split-second with a half-hearted punch while distracted.
** The Thousand Master himself, and a bit of a sore point. When a threat level of Ala Rubra was placed, with Zect and Eishun listed as the most dangerous... then Nagi was mentioned as, "oh, and this kid is pretty good too," complete with his own picture, which is suddenly scowling. Oh, and Zect looks like an eight-year-old while Nagi was fifteen or so.
*** Recent events seem to say that [[spoiler: Zect [[strike:is]] was [[ReallySevenHundredYearsOld over 2000 years old]].]]
* ''DigimonTamers'' is notorious for this, as every single one of the main characters' families plays the JustAKid card. [[SpellMyNameWithAnS Jenrya's]] mom was probably the most memorable -- she was the only one who never really supported the idea of her son fighting, even after seeing him in action.
** ''[[DigimonTamers Tamers]]'' wasn't the only season to have a JustAKid situation. Iori/Cody got this treatment from his older teammates, two of whom (T.K./Takeru and Kari/Hikari) conveniently forgot that Iori/Cody is two full years older than they were during their first adventure with the Digimon (at least that's the age gap in the American version. Correct me if that isn't universal).
*** Issuing requested correction: Iori is ''one'' year older than Takeru and Hikari were when their adventures began.
* In ''HighschoolOfTheDead'', despite most of the main cast being high school age and obviously competent from the reader's perspective, they receive this treatment once they reach the Takagi mansion. Fortunately, the cast gets their chance to prove themselves.
* In ''{{Eyeshield 21}}'', this was the reason why Mamori didn't want Sena to join the football team, as she still sees him as someone who needs to be protected by her. And this plays a major role in [[SelectiveObliviousness why she cannot realize]] that Sena is in fact Eyeshield 21.
* Iris from ''Anime/{{Pokemon}}'' has a rather...odd...habit: calling [[TheHero Ash]] a kid whenever he says something she doesn't like or does something not smart. In fact, she does it often in plenty of episodes...even though ''she's'' a kid herself!
[[/folder]]

[[folder:Comics]]
* ''[[SpiderMan The Amazing Spider-Man]]'': Spidey gets unmasked by Dr. Octopus in an early issue, but thanks to Peter Parker's youth (and Spidey's poor performance in the proceeding fight) [[YourCostumeNeedsWork neither Ock nor the assembled crowd believe Parker is really Spidey]], assuming that Peter just donned a Spider-Man costume to play the hero. Years later, when Spidey unmasks on national TV, Doc Ock goes on a rampage fueled by the humiliation of being constantly beat by a high-schooler.
** Subverted a lot in ''ComicBook/UltimateSpiderman'', where Spiderman is normally a well-respected threat to the bad guys until he begins to quip. His talking points normally date him (making pop-culture references or nave assumptions), prompting the bad guy to reply along the lines of "Wait, how old are you?"
* ''ComicBook/TeenTitans'' is built on this trope.
* The ComicBook/{{Runaways}} have to deal with this kind of treatment all the time from adult superheroes. This doesn't mesh well with the runaways' ingrained belief that AdultsAreUseless ''at best'' thanks to the whole "parents are evil supervillains plotting to wipe out humanity" thing that shattered their ability to trust adults. In their well-meaning efforts to look out for the kids' well-being, the adult heroes are just reinforcing the idea that the runaways can't ever trust adult authority figures.
* The backup feature in one issue of ''ComicBook/{{Tomahawk}}'' was about Brass Buttons, Stovepipe, and Dan Hunter (none of them even 20 yet) embittered by the other Rangers looking down on them because of their youth. Naturally they end up saving the day later.
[[/folder]]

[[folder:Fan Fics]]
* In ''FanFic/TheCaptainOfTheVirtualConsole'', Rocket Grunts consider Red to be a kid beneath their notice. He proves them wrong.
[[/folder]]

[[folder:Films -- Animation]]
* This was the main plot of ''TheSpongebobSquarepantsMovie''. [=SpongeBob=] got this from nearly everyone in the movie as a reason he's not capable of doing what he sets out to do. Of course, he does prove himself.
** This trope name is also the name of the third song on the movie's OST, performed by {{Wilco}}.
[[/folder]]

[[folder:Films -- Live-Action]]
* ''Film/TheNeverendingStory''. The Prime Minister (or whoever he's supposed to be) didn't want Atreyu the child, he wanted Atreyu the warrior. Atreyu just shrugs and says he is the only one of his tribe with that name and they can take it or leave it. They take it.
* In ''Film/XMenFirstClass'', when {{Magneto}}, [[ArchEnemy of all people]], suggests that he and Xavier train the young mutants to fight Sebastian Shaw and the Hellfire Club.
--> '''Xavier''': They're just kids.
--> '''[[{{Magneto}} Erik]]''': No. They ''were'' kids.
* ''Film/{{Skyfall}}''
--> '''Q''': I'm your new Quatermaster.
--> '''Bond''': You must be joking.
--> '''Q''': Why, because I'm not wearing a lab coat?
--> '''Bond''': Because you still have spots.
[[/folder]]

[[folder:Literature]]
* In ''Literature/RomanceOfTheThreeKingdoms'' the veteran generals of Wu were reluctant at first to follow the orders of their new chief strategist Lu Xun because he was just "a mere young scholar". They later gave him their full support after seeing how effective the strategy was in curb-stomping the invading Shu forces.
* This trope is generally inverted in ''{{Duumvirate}}'' because everyone knows how dangerous young engineereds are, but one [[TooDumbToLive poor fool]] messes with a certain four-armed boy escaping from an AmusementParkOfDoom. The kid's a fraction his size, WhatCouldPossiblyGoWrong
* ''[[TheChroniclesOfNarnia Prince Caspian]]'': Trumpkin doesn't even try to hide his initial disappointment to find that the powerful kings and queens who ruled Narnia during the Golden Age have come back as ''children'' (YearInsideHourOutside complicates things that way).
* In the ''NightWorld'' series, made vampires are frozen at whatever age they are turned at, and lamia (vampires that can eat, have children, etc.) can stop their physical aging at any time they want. This ends up meaning that several people who have to fight vampires have to silently recite something along the lines of, "They're not really kids." Amusing, considering even vampire kids who are young would still be rather dangerous to a human.
* In ''Hunger'', the second book in the ''Literature/{{Gone}}'' series, by Micheal Grant, this is the excuse of almost everyone for not working, because every character is under 15.
* Literature/HarryPotter saves the day about once a year, but the good adults, with the exception of [[ReasonableAuthorityFigure Dumbledore]], treat him like a child until the sixth book or so. In particular, using this trope was [[MisplacedKindergartenTeacher Umbridge]]'s ''modus operandi''. To be fair, even disregarding the number of near-death experiences, hairs-breadth-escapes, and hideously one-sided battles Harry's had to face, you can't blame the adults for trying to prevent him from getting blown up or having his soul sucked out.
** But you can blame them for not sharing critical information which directly concerns him simply because they think he can't handle the AwfulTruth. Especially when they do this over and over again and Harry always finds out anyway.
* Appears a lot the ''YoungWizards'' series, mostly used by parents. But in book 4, 14-year-old Nita uses this trope on a month-old kitten bard; the kitten is not amused, and starts lecturing....
* "A terrorist doesn't let strangers into her flat because they might be undercover police or intelligence agents, but her children bring their mates home and they run all over the place. The terrorist doesn't know that one of these kids has bugged every room in her house, made copies of all her computer files and stolen her address book. The kid works for {{CHERUB}}."
* The frequently-underestimated eleven year old chemistry genius and proto-goth-chick Flavia de Luce solves mysteries in books like "The Sweetness at the Bottom of the Pie" and "The Weed That Strings the Hangman's Bag." In the latter, the constabulary are infuriated she is always better informed than they are and put it down to the fact that as a kid, people open up to her. (The fact is, she's also smarter than they are.)
* [[Literature/TheHobbit Thorin Oakenshield]] was equivalent in age to a fourth or fifth grader when he fought at Nanduhirion and earned his nickname. [[LordOfTheRings Din Ironfoot]] was even younger at that battle, where he slew an orc-chieftan. And not just any orc chieftain but ''Public Enemy Number Two[[note]]Smaug was Public Enemy Number One at the time.[[/note]] Azog''!
* Children under fifteen are by default looked down on in ''ASongOfIceAndFire'', but they can definitely prove themselves and gain a following if they're strong enough. Women are treated the same way. Being both of these things, Daenerys likes to twist this trope to her own benefit whenever an advisor or commander voices some opinion that she disagrees with or believes is short-sighted.
--> '''Daenerys''': I am only a young girl and know little of such matters, but it seems to me that ''[voices an opinion she has no intent of changing]''.
* At the end of ''Literature/TunnelInTheSky'', [[spoiler: the stranded kids are finally rescued. The adults treat them like they're still children when the students survived years on an alien world and built a thriving, civilized colony]].
* ''Literature/ASeriesOfUnfortunateEvents'' has the Baudelaire orphans who are a lot more intelligent than they are given credit for, and one of them is a ''baby''. They learn [[AdultsAreUseless not to go to adults for help]] because many of the adults will either [[YouHaveToBelieveMe not believe them]] or are just idiots.
* ArtemisFowl has had it impressed on him many times that the hardest part of being a pre-teen [[TheChessmaster criminal mastermind]] is getting people to take you seriously, especially when dealing with his own race. Faeries tend to respect him more, though they still get irked at being outsmarted by a [[FantasticRacism mud boy]].

[[/folder]]

[[folder:Live-Action TV]]
* ''Series/BuffyTheVampireSlayer'': Buffy, at least during the high school years. It disappears largely after then, because everyone in Sunnydale (and beyond) has apparently heard of Buffy and is no longer surprised at her abilities. The trope was back in full swing during season seven, with the training of Dawn and the Potentials.
** Normally Dawn complains about being called a kid (to be fair, by the end of the show, she's older than Buffy was when she started Slaying), but [[OutOfCharacter one time she refers to herself as just a kid]]. Nobody cares because, well:
-->'''Dawn:''' [[CrowningMomentOfFunny It's like a meat party in my mouth.]] ''(pause)'' [[ThatCameOutWrong Okay, I'm just a kid and even I know that sounded wrong.]]
* ''DoogieHowserMD'': The premise: medical doctor who is just a kid. Faintly based on a real-life example.
* ''{{Sliders}}'': Quinn Mallory
* ''TheWire'': Omar Little, one of the lead characters, dismisses many young players in the Baltimore drug trade because they're "just kids", including using the phrase exactly to describe Michael, who is meeting with Marlo, in late season four. One such child, [[spoiler:Kenard]], is looked at by a Baltimore police officer as an example of how Omar's influence and brazen antics have spread to young, impressionable children, who view him as a hero. Near the end of the series, [[spoiler:Omar is unexpectedly gunned down by Kenard, and had dismissed the child as a threat when he walked into the store]].
** The trope is then used word for word in the season five finale. [[spoiler:Michael]] has become a stick-up boy in Omar's mould, and when he holds up [[spoiler:Marlo's "bank"]] is told "Shit, you just a boy!"; [[[foldercontrol]]

[[folder: blam ]]
] "And that's [[OnlyAFleshWound just your knee.]]"
* ''Series/GameOfThrones'': [[BadassGrandpa Tywin Lannister]] dismisses the 18-year-old [[YoungAndInCharge Robb Stark]] as a threat because of this, figuring that he'll probably run back home to the North at the first sight of battle. [[spoiler:He is oh so very wrong. When the dust settles, his son is a prisoner of war, and half his army has been destroyed. Turns out that Robb is actually quite the tactician.]]
* On ''DiagnosisMurder'', Dr. Jesse Travis got this from at least one elderly patient.
[[/folder]]

[[folder:Music]]
* "Just A Boy" from the Music/{{Kiss}} album ''Music/MusicFromTheElder''.
* "Just A Kid" by Wilco.
[[/folder]]

[[folder:Myths & Religion]]
* OlderThanFeudalism: Jeremiah, from ''Literature/TheBible''.
* In the ''Literature/TainBoCuailnge'', Queen Medb writes off Cu Chulainn when he first issues a challenge against her forces. Sure, Fergus says he's an unstoppable badass that outclasses all of her men, but he's just a seventeen-year-old boy - [[TemptingFate what chance could a single teenager possibly have against an entire army of battle-hardened soldiers?]]
[[/folder]]

[[folder:Video Games]]
* In the NES version of ''VideoGame/FinalFantasyIII'', one of the villagers in Ur thinks the four Onion Kids are crazy because they want to save the world.
* In ''{{Dissidia}} 012 Duodecim Final Fantasy'', [[VideoGame/FinalFantasyXII Vaan]] thinks that the Onion Knight is way too young to be fighting with the rest of them, and elects to be his [[BigBrotherInstinct "older brother"]]. This mainly consists of him trying to get Onion Knight to take it easy at every term which ''really'' ticks off the Onion Knight, who's surprisingly mature and strong for his age.
* Mission Vao in ''KnightsOfTheOldRepublic'' is constantly annoyed this trope, to the point of it being a BerserkButton. She's just fourteen and sounds like a typical teenager, except for the part that when she demands to be taken seriously, she has good reason. You can avert actually treating her like this, though.
** Seeing as she survived ''on her own'' in [[WretchedHive one of the worst slums in the galaxy]] after her brother ran off, when she is an age, gender, species, and attractiveness level (nubile, female, pretty-looking Twi'lek of uncommon coloration) that would have pigeonholed her into prostitution, slavery, or worse '''and''' frequently explres tunnels and passages in the Undercity where even the party's [[ProudWarriorRaceGuy Mandalorian mercenary]] won't go without a full entourage of armed men, even ''without'' [[TheBigGuy Zaalbar]] for backup, her annoyance at being blown off as a kid is pretty justified. Mission is definitely LittleMissBadass.
* {{VideoGame/Bastion}} has this Averted, as the main protagonist is not only the one of the few survivors of {{The End of the World as We Know It}}, but he's Only 16 or so. Then he gets {{More Dakka}}. A hammer, shotgun, rifle, bow, flamethrower, machete, spear, indestructible shield, and an OP cannon. More than Enuff Dakka for such a young Kid, huh? Even the Narrator thinks so.
--> Rucks: (Kid uses Army Carbine and [[spoiler:Calamity Cannon]]) "Kid makes me nervous sometimes strutting around with all those guns."
** It gets better. Yup. {{Macross Missile Massacre}}
---> Rucks: (Kid uses Galleon Mortar and [[spoiler:Calamity Cannon]]) "OK, now that's just plain overkill. I mean, come on."
** But then again, in a vague spoiler, he did [[spoiler: lose a lot through his early life at the Rippling Walls]]. {{Deus Angst Machina}} Much?
* ''VideoGame/CastlevaniaPortraitOfRuin'': Charlotte Aulin. Everyone treats her like a kid... even her partner.
* ''FireEmblem''
** Played for laughs in ''[[VideoGame/FireEmblemJugdral Fire Emblem: Genealogy of Holy War]]'':
-->'''Sylvia''': ''My name is Sylvia, but you can call me 'Sylvie'!''\\
'''Sigurd''': ''Huh? Just a little girl. You better find a place to hide, it's dangerous here.''\\
'''Sylvia''': ''Little... GIRL!? You ever see a little girl with [[GagBoobs THESE!?]]''
** Played straight in ''VideoGame/FireEmblemTheSacredStones'' with Ewan, his older sister and mentor still tend to see him as a little boy (the latter less so than the former, however, Saleh is shown to acknowledge and praise Ewan's skills despite the scoldings).
** Also played straight with Rolf in [[VideoGame/FireEmblemTellius Tellius games]] (less so in ''Radiant Dawn'' since [[TimeSkip he does get older]]) by his brother Boyd, and the majority of the people on his support list, excluding the [[IllBoy sickly priest Rhys]] and his mentor [[TallDarkAndSnarky Shinon]], for the most part. Some of his support conversations basically begin with someone telling him that he's too young to be on a battlefield, [[BerserkButton while he denies it vehemently]], and later proves them wrong at the A support level.
* ''Franchise/TheLegendOfZelda'' series: The younger Links occasionally get this treatment. In game, the general populace of Hyrule have various reasons why they don't believe Link, despite him wearing the clothes of the hero, ranging from "nice fancy dress" to "you playing let's-pretend-we're-the-hero-of-time" to having it become tradition in various places that children wear the same clothes as the legends tell off and also other such reasons. As a whole the series justifies people treating Link like he's not a hero in that, in real life, [[RealityEnsues if you saw a kid come up to you in Robin Hood clothes, would you believe that they're the reincarnation of Robin Hood?]]
** In the ''VideoGame/TheLegendOfZeldaMajorasMask'' manga Link also has to deal with this when he's traveling the world. He's invited to show a group of soldiers in training how to fight; the guy in charge knows that Link is a little badass, but the trainees mock him. Until he beats them up, of course. It's then commented that he fights like a man but when it comes to food, he acts like a kid. ''Majora's Mask'' itself (as well as the manga) uses this trope when Link is turned into a Deku Scrub, too.
*** Amusingly averted after Link regains his normal Hylian boy form. Children aren't allowed outside the city walls, it's too dangerous, but since Link has a sword the guards will let him do whatever he wants, despite the fact that he's ten and barely comes up to the guards' waist. The best part about that is that the guard ''apologies for treating him like a child''.
** In ''VideoGame/TheLegendOfZeldaLinksAwakening'', a pair of boys playing catch will give you tips on what to do in the game, followed by "I don't know what that means, I'm just a kid".
** Even older incarnations of Link aren't immune. When Link revives Scrapper in ''[[VideoGame/TheLegendOfZeldaSkywardSword Skyward Sword]]'', the robot in question refuses to give him a modicum of respect (''saving his life'' only warrants a reluctant offering of "obligatory gratitude"), calls him a child, and then takes to taking jabs at his height by permanently nicknaming him Master Shortpants.
* ''VideoGame/MegaMan8'': Tengu Man looks down (literally) on our hero and says, "It's just a kid. Don't make me laugh." in some instances in the English releases.
** Which is kind of a silly case, when you think about it. Mega Man might look and act like a child at some points, but he's actually ''older'' than every other robot in the franchise save Proto Man.
*** [[MyLifeAsATeenageRobot Tengu Man was BUILT just last year, but he was DESIGNED as an adult.]]
** If playing as X in ''VideoGame/MegaManX 4'', Frost Walrus says this pre-battle: "They sent a kid like you after me? I promise to end this quickly". If playing as Zero, he says: "What's that blonde kid up to?! I don't have time for you junior!"
** Also from the metaseries is Hope Stelar of ''VideoGame/MegaManStarForce'', where she calls her own son (and the hero of the game) "Just A Boy" in the third game.
** In ''VideoGame/MegaManZX Advent'', Atlas, the Mega ([[ViewerGenderConfusion Wo]])Man of Fire, tells young Thetis, Mega Man of Ice and fellow member of a QuirkyMinibossSquad that he's just a kid and wonders why he was picked to be Model L's [[TheChosenOne Biomatch]] [[note]]The [[TransformationTrinket Biometals]] are the {{Legacy Character}}s of [[VideoGame/MegaManX X, Zero]], [[VideoGame/MegaManZero X's Four Guardians, and Dr. Weil]], FYI.[[/note]] Slightly irked, Thetis is quick to mention that as a teenager, there isn't much of a gap between them age-wise.
* NES ''NinjaGaiden'' (For NES): Ryu Hayabusa mistakes MIB agent Irene Lew as "Just a girl. Get out of here." He is promptly shot and captured.
* Used frequently in the ''{{Pokemon}}'' games. Every evil "team" has at least one member that says some variation of this, despite the fact that physical age has no effect on battles. Even Team Rocket continues to do this in the second generation games, which is surprising, considering that it was a kid who caused them to disband three years before.
* ''VideoGame/SonicAdventure2''. Eggman taunts Tails: "You're just a kid. You couldn't beat me in a hundred years!" This was extremely stupid of Eggman seeing that Tails may have managed to see him off once before in that story and actually managed to defeat him decisively when he was attacking station square in the previous game in a head to head... [[PintSizedPowerhouse without his mecha.]] Whether Eggman ends up eating his words depends on whether you're playing the hero or dark story.
* Happens in the ''VideoGame/TalesOfSymphonia'' games with Genis, the [[TeenGenius Kid Genius]] SquishyWizard of the party.
* Laharl of ''VideoGame/{{Disgaea|HourOfDarkness}}'' has gotten quite a bit of this from both Etna and '''Captain Gordon, Defender of Earth!''' Etna uses it to legitimately call him out on his [[RoyalBrat brattiness and emotional immaturity]] while He Who Has NoIndoorVoice is just incapable of believing that some [[BadassAdorable tiny little punk]] is stronger ''and'' smarter than him.
* In ''[[VideoGame/FinalFantasyX2 Final Fantasy X-2]]'', Shinra responds to questions he doesn't know the answer to with "I'm just a kid."
** At one point, Yuna actually calls him out directly on this. She wants to communicate with the cactuars in the Cactuar Nation, but Benzo, the Al Bhed kid who understands their speech, isn't around. She asks Shinra if he can communicate with them and Shinra gives his standard excuse, to which Yuna responds that Benzo is also just a kid. Shinra seems ''very'' put out by this.
* ''Videogame/{{Earthbound}}''
** Considering the protagonists are all in their early teens: "At times like this, kids like you should be playing video games!"
** Also in ''Earthbound'', the sea captain who is ferrying the group to Scaraba exclaims that he thought that the foursome were just a group of kids upon them defeating the Kraken.
* ''Videogame/BackyardSports'': This is the way Sally Dobbs acts toward her brother Ronny.
* One of the motivating factors behind [[spoiler: Naoto's]] shadow in ''VideoGame/{{Persona 4}}''.
** Also seen in the Good Ending when [[spoiler: Adachi]] taunts the team by saying things along the lines of "Students should stay home and study." (As opposed to, you know, bringing him to justice.)
* A RunningGag in the fourth case of ''VisualNovel/AceAttorneyInvestigations'' was that everyone was dissing the young Miles Edgeworth and Franziska Von Karma as just kids, even though Edgeworth was already a prosecutor.
* ''VisualNovel/ApolloJusticeAceAttorney:'' Almost everyone in the cast brushes off Apollo and Trucy as kids trying to play as grown ups, even though Apollo IS a Defense Attorney and [[OlderThanTheyLook 22 years old]].
* In ''VideoGame/StarFox Assault'', Wolf continually calls Fox a "pup". [[AllThereInTheManual Nowhere do they explain]] they have retconned Wolf's age to be 6 years older than Fox.
* In the non-canon ''Yu-Gi-Oh GX! Tag Force 1'', [[BigBad Kagemaru]] say this to the player during their second duel (after going from being stuck in a machine to being youthful, a glowing aura, and eight-pack abs) when he's losing.
* Paige tries treating the others as kids in ''[[{{TCT RPG}} The Colour Tuesday,]]'' at which point Alex points out that she's the same age as the rest of them.
[[/folder]]

[[folder:Visual Novels]]
* Prevalent in {{Nasuverse}} works. Then again, the one saying it is usually [[OurVampiresAreDifferent far]] [[AllMythsAreTrue beyond]] mere humans.
** ''{{Tsukihime}}'': Nero to Shiki, who proceeds to destroy over a hundred of his beasts.
** ''FateStayNight'': Gilgamesh to Shirou, who by then has the perfect counter-ability (Avalon or [[FieldOfBlades Unlimited Blade Works]], [[AlternateContinuity depending]])
[[/folder]]

[[folder:Web Animation]]
* ''WebAnimation/HomestarRunner'': Parodied in the Strong Bad E-Mail "japanese cartoon".
-->'''1-Up:''' Hey, Stinkoman! Everybody says you're the guy, but I want to be the guy too!\\
'''Stinkoman:''' No way! You're just a kid! Maybe when you're '''older'''!
** And then flipped around in ''VideoGame/{{Stinkoman 20X6}}'', where 1-Up ''himself'' says that he can't rescue Pan Pan alone because he's just a kid. (Maybe when he's older...)
[[/folder]]

[[folder:Web Comics]]
* Lampshaded in [[http://www.superstupor.com/sust04092008.shtml this]] ''Webcomic/SuperStupor'' strip. The BigBad thinks the trope, but his GenreSavvy henchman quits on the spot. Of course, the BigBad [[GenreBlindness doesn't believe him]] and gets roasted.
[[/folder]]

[[folder:Web Original]]
* Both the five protagonists and two of the antagonists of the web fiction serial ''Literature/DimensionHeroes'' fit into this trope.
* Vista, in ''Literature/{{Worm}}'', is a thirteen-year-old superheroine on a team of older teenagers. She's ''also'' the member of the team with the most actual experience as a superhero, because she's had her powers since she was ''eleven.'' It frequently leads to her experiencing this trope.
* A rather [[http://www.youtube.com/watch?v=6IcZbluiA1s vulgar example]] brought to you by the WebVideo/TheTourettesGuy. Apparently, asking for Captain Crunch cereal is enough to get the "Just A Kid" treatment ''and'' some very blue-mouthed put downs if you're Danny's son.
[[/folder]]

[[folder:Western Animation]]
* ''WesternAnimation/AvatarTheLastAirbender'':
** Despite the page quote, the show averts this in that Aang is instantly recognized as the most important person on the planet by most people he encounters, and will react to him by either giving him respect, wanting him to complete a dangerous task for them, or attacking him on sight, and will usually result in Aang's pursuers homing in on his position regardless. This aversion is a distinctly mixed blessing to say the least.
** It's simultaneously averted and played straight (by Yue and Aang respectively) in the season one finale (which, coincidentally was aptly named "TheSiege of the North").
-->'''Aang:''' I must have taken out a dozen Fire Navy ships, but there's just too many of them. I can't fight them all.\\
'''[[TheChiefsDaughter Yue]]:''' But, [[BecauseDestinySaysSo you have to!]] You're the [[TheOnlyOne Avatar!]]\\
'''Aang:''' I'm just one kid. ''(buries his head in his arms)''
* ''WesternAnimation/{{Ben 10}}'': Ben occasionally runs afoul of this, though never for very long: VoluntaryShapeshifting helps you escape this trope. Rather bizarrely, though, he often does find himself falling victim to this response all over again after a battle, when he changes back into his human form and the supporting character of the week realizes that he's a "just" a shape-shifting, superpowered kid rather than an alien.
* ''JusticeLeagueUnlimited'': Spoofed when Flash laments the rest of the League's reluctance to take him seriously... while playing Rock'em Sock'em Robots. It's also played straight in the season finale when Flash answers [[FanNickname Luthorac's/Brainthor's]] taunt of "Are you going to fight me, ''boy?''" by [[LetsGetDangerous deciding to get dangerous for once.]] [[CrowningMomentOfAwesome Epically.]]
* WesternAnimation/DannyPhantom gets this a few times; twice from Vlad, once from Clockwork, although the latter is justified since he was trying to explain (in short) the nature of time to someone who's probably barely passing pre-algebra.
** Also referred to in the opening theme. ("...Danny Fenton, he was just fourteen, when...")
* A huge theme of ''PhineasAndFerb'' is the fact they ''are'' just kids, yet still manage to do so many bizarre and amazing things; this is the main reason that their mother [[RefugeInAudacity never believes Candace]] when [[CassandraTruth she tries to bust them]].
-->'''Adult:''' [[MadLibsCatchPhrase Aren't you a little young to be [insert whatever Phineas and Ferb are doing]?]]\\
'''Phineas:''' [[BluntYes Yes]], [[RunningGag yes I am.]]
** Parodied when Candace once asks the boys (renowned for making bizarre inventions) why they couldn't just create some way of fixing their rocket ship without necessitating a space walk. The boys simply stare at her for a moment before Ferb comments, "Candace, we ''are'' just kids."
* Throughout the ''FostersHomeForImaginaryFriends'' episode "Frankie My Dear", Bloo uses this as his excuse as to why he thinks he's better for Frankie than Mac is. Mac promptly throws it back in his face, since he imagined Bloo when he was three, making Bloo all of ''five years old'', with the immaturity of a whiny toddler to match.
* This trope is a more or less constant worry for Ma-Ti of ''CaptainPlanetAndThePlaneteers''. True, except for Gi they're all "kids", but Ma-Ti has the added disadvantage of just being ''twelve'' (aside of, well, the WhatKindOfLamePowerIsHeartAnyway deal).
** Which was PlayedForLaughs in [[Website/ThatGuyWithTheGlasses Linking Up with Linkara's]] [[TheStinger Stinger]], [[spoiler:where WebVideo/TheNostalgiaChick and MarzGurl pretended to have slept with (a presumably aged up) Ma-Ti.]]
-->"I'm only fourteen!"
* ''WesternAnimation/TheAmazingChanAndTheChanClan'': "You're not old enough, Scooter."
* ''Literature/MaxAndRuby'': The character Max, despite being about four and not being capable of saying more than a few words at once, shows himself to be quite capable of either outwitting his older sister or helping her to get what she wants.
* Underestimating a KidHero? How about a kid VILLAIN? [[BrainyBaby Stewie]], from ''WesternAnimation/FamilyGuy'', shows signs of developing into a DiabolicalMastermind, yet his parents tend not to take him seriously. For example, he likes to read books like ''Literature/ThePrince'' and ''Literature/TheArtOfWar'', yet his mother interrupts him telling him those books are not for toddlers and he should be watching ''Series/{{Teletubbies}}'' instead. (Of course, he somewhat likes the show, but still...)
* Averted in "DragonBooster", where not only are the main cast all 16 or under (Moordryd being debatably 17), no one even mentions that Artha's 10 year old brother is going on the adventures with the group. Possibly explained by the only adults we see being Artha and Moordryd's fathers, and officials that are presumably upper class, but it's strange to only see adults in situations that simply could not be done by children (security heads and teachers), and no one thinks it's strange for the Down City racers to be primarily under 20.
** Of course, on the flip side, the Down City races are the lowest ranked races, and so of course the competitors would be younger. If we had seen some higher-ranked racers, they might have been adults who might even have taunted the heroes for being "just kids"
** Which still doesn't excuse no one being shocked that Lance (the above mentioned 10 year old) went on all the missions with Artha's team and the only person to even say "he's just a little kid" was Artha's AntiVillain rival Moordryd, and even then only after Lance was attacked. Other than that, people only refer to him as short. Clearly the standards are different in Dragon City.
* A theme on ''WesternAnimation/YoungJustice;'' the team initially formed when the original sidekicks felt their mentors weren't giving them as much respect as they deserved. The Justice League agreed to accommodate them (albeit with issues continued to be hammered out throughout the first season). And of course, it sometimes comes up with villains too; [[BlowYouAway Mister Twister]] actually claims to be disturbed to fight children and asks if they have any adult supervision.
** It also comes up when the Justice League discovers that one of their own members, [[{{Shazam}} Captain Marvel]], is [[OlderAlterEgo actually only ten]], leading to a vote about whether or not to keep him on. [[spoiler:They do]].
* In ''ThePenguinsOfMadagascar'' Skipper has used this phrase regarding Private a couple of times, sometimes to him, and sometimes when being a LargeHam. The best was in "Caught In The Web" when Private was taken away by Alice...
--> '''Skipper:''' HE'S JUST A BOY!!!!
[[/folder]]

[[folder:RealLife]]
* TruthInTelevision: There are some children who are really, really good chess players. If you see a kid playing chess in a park, you underestimate him at your peril.
** The same could be said about kids playing the most brutal Fighting Games in arcades.
* Several notable bands who are known as extremely talented have had teen members, Primus among them.
* There were those that thought that about Charles XII. ItSeemedLikeAGoodIdeaAtTheTime.
* All of Europe thought that about Maria Theresa. [[YouWouldntLikeMeWhenImAngry They proved mistaken]].
* No matter how old your are or how much experience or education you acquire you will always be a child in your parent's eyes.
** This could be part of the reason behind teenage rebellion. When teenagers start seeing that the world is seeing them as an adult and being given more responsibilities (being able to drive, vote, enlist in the military, etc.,) and you parents still see you as "my little baby," it's entirely possible that most rebellion is the child saying, "No, I'm not anymore." Most go in the wrong direction, but still as good a theory as any.
** Sometimes the opposite happens- being seen as that baby is meant in a meaningful, loving way, because they got the pleasure to raise you. Unfortunately, this isn't true for all families.
* If you have any elder siblings, they will always think of you as the baby, even if you qualify as a genuine badass CrazyAwesome.
* This was part of the real reason JoanOfArc's ability to lead an army was questioned. Women soldiers were not unheard of (especially as all the men were getting killed), some had even commanded, and it was not the first time someone had reported being asked by God to fight the English. It was the first time someone did all these things ''at the age of fourteen.''
* These Cracked Article
** ''[[http://www.cracked.com/article_20552_6-old-photos-kids-who-are-way-tougher-than-modern-adults.html 6 Old Photos Kids Who Are Way Tougher Than Modern Adults]]'' had photographs of kids who can put an present adult to shame.
** ''[[http://www.cracked.com/article_19862_5-kids-who-kick-ass-at-stuff-they-shouldnt-be-allowed-to-do.html 5 Kids Who Kick Ass at Stuff They Shouldn't Be Allowed to Do]]''

[[/folder]]

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