Miyagi: Don't know. First time you, first time me.
Daniel: Well, I figured you knew about this stuff. I figured you went to these before. Oh great, I'm dead. I am dead. You told me you fought a lot.
Miyagi: For life, not for points.
A character regarded as an expert or veteran regularly does something or operates something that you're supposed to have training or some sort of official certification for, such as a license. He may even be a mentor training a pupil.
It gets revealed that he doesn't actually have the official qualification. He may have been Incompletely Trained, or decided to side-step the system. Or perhaps he was denied the opportunity to qualify, but was able to "fake it till you make it." In some cases he may have a Phony Degree as part of the deception.
Unlike with an Anti-Mentor, he's actually competent, and obviously doesn't need the training or testing he didn't get, either because of his natural talent or from having been Taught by Experience by the time this is revealed.
Compare Anti-Mentor, where the "expert" is faking it (or is just very bad at teaching,) and Obsolete Mentor, who did have the training, but hasn't stayed up-to-date. Compare and contrast Back-Alley Doctor, where being an uncertified expert (in medicine) makes one hard to practice it openly, unlike in this trope.
Note: This trope only applies if the training or certification is expected within the context of the story, and its lack is a surprise or noted as unusual.
- The titular Doctor Blackjack is a super-surgeon who charges ludicrous fees for his services. A Running Gag is how other characters remark how he is an unlicensed doctor, and some plots are about how to make him get a license, which he always refuses. Then we find out WHY he refuses a medical license. Blackjack's in a vendetta against the corrupt officials which caused the death of his mother and disfigured his face. The money he charged goes to fund his revenge schemes, and taking the Hippocratic Oath would prevent him from exacting his revenge.
- Marvel Comics' villain Doctor Doom attended college in upstate New York alongside Reed Richards. Doom's experiments in transdimensional shifting blew up his dorm room and got him expelled before he'd attained a degree. Nevertheless, Doom's raw intellect has transformed feudal Latveria into a showpiece of Europe. Further, Doom studied the arcane arts, seeking to free his gypsy witch mother's soul from the lower netherworld. He has accomplished this with help from Doctor Strange, who privately conceded that Doom is qualified to become a Sorceror Supreme, despite never having trained under a master mage.
- Fowler from Chicken Run is believed to have been a pilot in the RAF and serves as an advisor; it turn out he was really the squadron mascot. When questioned about this he is confused that anybody ever thought he was a pilot in the first place: he is a chicken, the RAF does not have chicken pilots.
- In The Matrix Revolutions, when Captain Mifune is dying and tells the kid that's been assisting him to pilot his mecha, the kid claims he never finished the training for it. Mifune replies that he never did either.
- The Karate Kid (1984):
- Miyagi, a former street-fighter and decorated World War II veteran, is dismissive of karate the sport's use of belt color to denote skill level, replying "canvas" when Daniel asks him what belt he is. When filling out entry forms for the karate tournament, when he's told of the requirement that entrants be brown belt or higher, he puts Daniel down as a black belt.
- Mr. Miyagi gives Daniel his keys and tells him to drive his truck. When Daniel protests that he doesn't have a license, Miyagi replies "Me neither."
- The King's Speech: Bertie always refers to Logue as "Doctor" (despite Logue trying to get him to call him "Lionel") until he learns that Logue isn't actually a doctor. He's furious at the deception, although Logue points out he never referred to himself as a doctor, he's just used to helping people with speech problems.
- Discworld: In Raising Steam, the engineering genius who brings the first steam trains to Ankh-Morpork runs into bother when the Guild of Artificiers protest that he is self-taught and not a Guild member - so if he has never been apprenticed himself, how can he legally train others to build and maintain a railway system?
- Hagrid from Harry Potter is a teacher at Hogwarts, but never actually graduated, and was expelled and had his wand broken. He's only teaching there due to Dumbledore's intervention. Later it's revealed that he was framed, and he has his good name restored along with his wand. His expertise in the subject — Care of Magical Creatures — comes from years of being the Hogwarts gamekeeper and his hobby of breeding and rearing dangerous beasts. Also, while he's excellent at his chosen subject, he's actually a terrible teacher, in part because he doesn't seem to understand the danger his favorite animals have to children who don't have his monstrous size and strength.
- Sherlock Holmes: The criminal of The Dying Detective is stated by Holmes to be an expert in tropical diseases, not because he's a doctor, but because his plantations in southeast Asia put him in daily contact with them. This allows him to kill his victims with diseases the average London doctor (including Watson) has never heard of.
- Doctor Who: The Doctor is a genius scientist and seasoned adventurer, who can casually create Magic from Technology and regularly overshadows or outsmarts the smartest individuals of multiple different races. However, it's a recurring joke that they're considered very poorly qualified by Time Lord standards. Their companion and fellow Time Lady Romana reveals that they barely scraped through their exams on their second try, their former teacher Borusa considered them a lazy student who would never amount to much, and they openly admit to having failed the TARDIS piloting exam.
- M*A*S*H episode "Dear Dad, Again". Captain Casey is the latest addition to the surgical staff at the 4077th, and he's a superb surgeon. However, it's discovered that he's actually a sergeant and not really a doctor. He admits that he's also passed himself off as a teacher, a lawyer and an engineer. He's just never had the patience to actually earn a formal degree in any of the fields.
- Crossed with Obsolete Mentor in an episode of Scrubs. Dr. Townsend is a beloved, grandfatherly figure at the hospital, (which you might expect as he's being played by Dick Van Dyke) and even Mean Boss Dr. Kelso has a deep friendship with him. However, while Townsend is a legitimate doctor he has fallen way behind the times in terms of medical technique and has failed to become certified in or learn the new treatments that would be much more effective than the outdated ones he is still using. After using one of those outdated techniques almost causes a patient to die, Kelso and Townsend have a quiet confrontation and Kelso is reluctantly forced to let Townsend go from the hospital as a result.
Kelso: Say, listen, um... nowadays it has become sort of hospital protocol to do modified Seldinger in a case like this. You do know how to do one of those, don't you?
Townsend: [after a slight hesitation] Of course.
Kelso: Because the patient in bed number 2 needs one. Mind doing it for me?
Townsend: [getting defensive] What the hell is this all about?
Kelso: I was just looking over your files and uh... you osteoporosis patients aren't on bisphosphonates, your diabetics aren't on ACE inhibitors... Doug, a lot of your treatments are pretty out of date.
- Shed, The Medic from early episodes of The Expanse, faked his medical degree and got a job on the Canterbury just to get away from a drug dealer that he owed money to. However, while far from an expert, (and despite his treatments being the subject of much ridicule by the rest of the Canterbury's crew) he's apparently not completely hopeless as a medic, as he's able to save Alex's life during an emergency.
- Regina Spektor's "Older and Taller" is about an older person nearing retirement, who's hiring their own replacements, but the lyrics also clarify:
All the lies on your resume,
Have become the truth by now,
And the things that you never did,
Have become your youth, somehow,
You know everything by now.
- Sammie from The Zombie Hunters had absolutely no background in medicine before becoming a medic in a post Zombie Apocalypse world, she did it purely because in the wastelands where she was living doctors and medics were so rare they were valued highly by the community and guaranteed good treatment. Due to a lot of experience with people getting wounded, and studying old medical books, she eventually became a competent medic.
Sammie: No one shoots the medic. You know doctor shit? You get treated like royalty out there. I caught onto this and faked it. ...I didn't know anything about doctor shit. I just put on a medic badge and did shit I saw on TV. Some of it worked, some of it didn't. Eventually I got kinda good at it.
- Louis Pasteur developed the rabies vaccine, but his lifesaving experiment (injecting a boy who'd been bitten by a rabid dog with the vaccine) could very well have gotten him arrested for practicing medicine without a license. Downplayed in that while he never did get a medical license, he wasn't exactly a random ignoramus either: he was a chemist and microbiologist who'd found a way to sterilize foods by briefly heating them to kill germs, and the procedure itself was conducted by licensed doctors who later defended his actions.
- As noted above in Film, Lionel Logue, who helped George VI overcome his stutter, was not actually a trained or certified speech therapist. What he was an amateur stage actor with a remarkable talent for doing voices and a commanding public speaking presence, who earned a reputation as a teacher on the subject. He got into speech therapy by volunteering to help WWI veterans overcome their PTSD-induced speech impediments, and became so prolific at it that he opened a practice.
- Because of the nature of the martial arts he studied, Bruce Lee never had anything like a formal rank or certification. He also had no training in nutrition or exercise science. Regardless, he was considered a world-renowned expert in all of those fields.
- It was common to lawyers in the early days of the United States to be admitted to practice law without a law degree, but they still had to study under another licensed attorney for a set number of years, and still had to pass the bar examination. However, the anarchist lawyer Lysander Spooner refused to do either, simply because he resented the idea of the organized bar having a monopoly over professional licensure. He did study under two lawyers, but for three years rather than the legally required five. He was no amateur, though; part of the reason why he didn't complete his term was because his mentors believed he was already ready to practice law and sympathized with his belief that he should be able to practice without state-imposed restrictions. Nowadays he's remembered as the first and most influential of American anarchist political theorists, and his writings on Constitutional jurisprudence (particularly with regards to slavery) heavily influenced the abolitionist Frederick Douglass.