History YMMV / HappyDays

* DarkerAndEdgier: By the final season. Well, as D&E as you could be with this show. More dramatic moments (among them an AttemptedRape of Joanie), the use of "hell" and "damn", and Fonzie showing more weakness.

* BaseBreakingCharacter: Chachi-nated, or De-Chachi-nated? Nick at Nite even made a marathon out of this premise, and viewers got to vote. He was liked by fangirls for being a MrFanservice and his relationship with Joanie, while other viewers found him an unnecessary addition to the cast with an annoying CatchPhrase.

%%* BaseBreakingCharacter: Chachi-nated, or De-Chachi-nated? Nick at Nite even made a marathon out of this premise, and viewers got to vote.

* HarsherInHindsight: Joannie and Chachi's romance was irrevocably ruined after Scott Baio's insensitive statement that Erin Moran deserved her early death because of her drug addictions.

* BaseBreakingCharacter: Chachi-nated, or De-Chachi-nated? Nick at Nite even made a marathon out of this premise, and viewers got to vote.

* TheScrappy: Roger, and really anyone introduced in season 8 and beyond.

* BaseBreakingCharacter: Chachi-nated, or De-Chachi-nated? Nick at Nite even made a marathon out of this premise, and viewers got to vote.

* BaseBreakingCharacter: Chachi-nated, or De-Chachi-nated? Nick at Nite even made a marathon out of this premise, and viewers got to vote. This got even worse when Scott Baio became much more open about his extreme right-wing political stance in 2016, as one of the few Hollywood celebrities to openly endorse Donald Trump during his presidential campaign.

* TheScrappy:
** Roger, and really anyone introduced in season 8 and beyond.
** Chachi was ''always'' [[TheScrappy The Chachi]]. He was popular with the girls, but retroactively, amongst older fans? Please.

* MorePopularReplacement: Before Chachi, in early seasons Fonzie had another younger cousin named Spike who was also an AbhorrentAdmirer to Joanie (like Chachi in the beginning) and completely disappeared after season 4. Chachi is introduced in season 5 in a similar role, but is eventually PromotedToLoveInterest and ends up becoming a main character until the end of the show. It helps that the character was very popular with teenage girls.

* HilariousInHindsight: In one episode, a martial arts class is taught by Arnold, played by Creator/PatMorita. Happily, [[Franchise/TheKarateKid Daniel-San]] was a better student than [[ButtMonkey Richie]].

* DarkerAndEdgier: By the final season. Well, as D&E as you could be with this show. More dramatic moments (among them an AttemptedRape of Joanie), the use of "hell" and "damn", and Fonzie showing more weakness.

** Fonzie in the first two seasons, so much that he became a BreakoutCharacter and was promoted to second billing, after Ron Howard.

* HilariousInHindsight: In one episode, a martial arts class is taught by Arnold, played by Pat Morita. Happily, [[Film/TheKarateKid Daniel-San]] was a better student than [[ButtMonkey Richie]].

* HarsherInHindsight: Joannie and Chachi's romance was irrevocably ruined after Scott Baio's heartlessly cruel statement that Erin Moran deserved her early death because of her drug addictions.

* EarWorm: C'mon, sing it with me: "[[TitleThemeTune Sunday, Monday, Happy Days...]]".

* ReplacementScrappy: Roger.

* BaseBreakingCharacter: Chachi-nated, or De-Chachi-nated? Nick at Nite even made a marathon out of this premise, and viewers got to vote.

* CrowningMomentOfFunny: Fonzie's been using "Sit on It!" for years, to great reaction. When ''Marion'' of all people uses it on ''him'', the reaction from the crowd and Fonzie himself was priceless.

* SeasonalRot: It started out as a very cool, low-key show, then became the ideal version of a standard sitcom with a StudioAudience. It'd started getting worse (the Trope-Named Shark-Jump) even before Richie left, but only got worse after that. Fonzie got a temporary full-time girlfriend for one season, and things got increasingly worse with gimmicks and nonsense until a thankfully fantastic final episode.
* SomeAnvilsNeedToBeDropped: According to Garry Marshall, "Richie Almost Dies" was written for this reason. He explained that he was contacted by counselors working with abused children who watched the show. These kids refused to cry and kept their emotions under wraps, so Marshall wanted to have Fonzie go through an emotional breakdown in order to show these kids that it was okay to cry.

** Roger, and really anyone introduced in season eight and beyond.

* HilariousInHindsight: In one episode, a martial arts class is taught by Arnold, played by Pat Morita. Happily, [[Film/TheKarateKid Daniel-San]] was a better student than [[ButtMonkey Richie]].
* TheScrappy: Roger.

* FranchiseOriginalSin: The moment of vertical ascension over an aquatic carnivorous animal is considered merely the point where Fonzie's flanderizing into a superhuman and the lost of the 1950s motif reached its zenith. Both those things had subtly been going on as the seasonal rot kicked in.

* BaseBreaker: Chachi-nated, or De-Chachi-nated? Nick at Nite even made a marathon out of this premise, and viewers got to vote.

** Mork was only supposed to be a one-shot character and his episode AllJustADream, but RobinWilliams' performance was such a hit that the episode was revised to make the events real after all and gave him his own spinoff.

* SomeAnvilsNeedToBeDropped: According to Garry Marshall, "Richie Almost Dies" was written for this reason. He explained that he was contacted by counselors working with abused children who watched the show. These kids refused to cry and kept their emotions under wraps, so Marshall wanted to have Fonzie go through an emotional breakdown in order to show these kids that it was okay to cry.

* SeasonalRot: It started out as a very cool, low-key show, then became the ideal version of a standard sitcom with a StudioAudience. It'd started getting worse (the Trope-Named Shark-Jump) even before Richie left, but only got worse after that. Fonzie got a temporary full-time girlfriend for one season, and things got increasingly worse with gimmicks and nonsense until a thankfully fantastic final episode.