History Main / ItSeemedLikeAGoodIdeaAtTheTime

** Hitler declaring war on the United States after the United States declared war on Japan. It may have been a case of HonorBeforeReason, as Japan and Germany were allies. Hitler wanted to be able to sink the American ships which were bringing much-needed supplies to England... but he didn't stop to think that the only reason that the United States wasn't doing more than providing supplies was because there was no state of war between Germany and the U.S.

* Emperor Tiberius was a paranoid tyrant and possible pedophile who arranged the deaths of his political enemies and more popular members of his own immediate family, alienating himself from anyone with power and influence in Ancient Rome. So reviled was he that when he finally succumbed to a fatal case of being smothered in his sleep by his abused nephews there was reportedly dancing in the streets of Rome. In an act of revenge the Senate decided to completely ignore his last will and testament regarding his succession, and appointed one of these abused nephews to the office of Emperor. This nephew, Gaius Caesar Augustus Germanicus, soon became synonymous with the decadence and insanity associated with the Caesars, and his better remembered by his nickname: UsefulNotes/{{Caligula}}.

** The Watergate break-in was itself this, as it was a "third-rate burglary" designed to find dirt on Nixon's political opponents and thus help ensure the landslide victory mentioned above... only to begin an intensive investigation into his dirty dealings which resulted in his eventual resignation in disgrace.

* This is a common occurrence on ''Series/Taskmaster'', which involves contestants assigned deceptively simple yet often incredibly goofy tasks to complete. The contestants are filmed completing them in isolation and are sworn to secrecy once they are done, meaning they have no idea how well (or not) they've done compared to the other contestants. They're also often forced to complete the tasks under time limits or similarly strict limitations, meaning that they often rush into doing the first thing they can think of regardless of how well-advised (or not) it is in hindsight. This means that a contestant will often leave the location shoot believing they've completed the task quite well only to cringe in mortification in the studio when their attempt is played back to an audience and shown in comparison with their competitors. For example, in Series 1 Frank Skinner completes a "do the best thing that will look amazing when played backwards" task by doing some push-ups, only to then have to watch the far more creative things his competitors come up with, leading to this:

'''Lucy [=McClane=]:''' You shot yourself!\\

* In the ''Series/DoctorWho'' episode “Cold War”, the Eleventh Doctor had reset the {-HADs-}, which caused the TARDIS to relocate to the South Pole and strand him and Clara on the Soviet submarine ''Firebird''.

* Owning a pet could turn into this trope in said pet's final years. The pain of watching a beloved dog or cat getting old, getting sick, and dying could make you wonder why you decided to get them in the first place considering the [[MayflyDecemberFriendship inevitable heartbreak]] experienced in the end.

[[quoteright:310:[[WebComic/ColourWheel https://static.tvtropes.org/pmwiki/pub/images/idea_0.png]]]]

* In ''Series/StarTrekTheOriginalSeries'', Spock's father, Sarek, gives this as the reason why he married Spock's human mother:

** Episode "The Emperor's New Cloak":

** The StockPhrase is also used in "The Way Of The Warrior Part I", when Sisko is rather surprised to find Dukat on the side of the Cardassian Civilian Government instead of Cardassian Military. Facing a revolution, Dukat had to consider what was best for... well, Dukat. (He tries to play it off as [[MyCountryRightOrWrong being an apolitical servant of the state and the people]], but he's fooling nobody and he knows it.)

** While they did succeed in beating Whitebeard, [[FamousLastWords with his final breath,]] [[DyingMomentOfAwesome Whitebeard confirmed that the world-famous treasure that belonged to Roger and that everyone was looking for did in fact exist.]] Fleet Admiral Sengoku reacted with a look of both fear and rage when Whitebeard did this, as he knew that with the word out, more pirates would now venture out to find One Piece, and an even bigger and more chaotic age of piracy would begin. With his final breath, Whitebeard basically [[AllForNothing invalidated every aim the World Government had by starting this war, making all of the Marine's spent resources and sacrifices a complete waste.]]

* Learned the hard way by [[HeartbrokenBadass spurned lovers]] who join the military, especially the Foreign Legion, to mend their broken heart. While a once-popular trope in fiction, reality is quite different; most military forces require at least a few years of service. A broken heart doesn't take that long to mend and these recruits may quickly regret their decision, especially since they can't simply quit like a normal job.

* In the finale of ''Anime/DigimonAdventure02'', AntiVillain [=BlackWarGreymon=] performed a HeroicSacrifice by using his body to seal the Japanese gateway in order to stop the [[DemonicPossession Myotismon-possessed]] Owikawa from getting to the Digital World. Two factors end up turning this into a SenselessSacrifice. First, threw a convoluted ricochet into another world, Myotismon (now [=MaloMyotismon=]) gets into the Digital World anyway, enabling him to launch his master plan to [[WhenDimensionsCollide claim both worlds as his own]]. Second, [=BlackWarGreymon=]'s seal makes it difficult for the Digidestined back on Earth to get to the Digital World in order to help the others.

--> '''Venus:''' What on earth?! Of all the things to put in here!
--> '''Mercury:''' It seemed like a good idea at the time!

[[quoteright:310:https://static.tvtropes.org/pmwiki/pub/images/idea_0.png]]
[[caption-width-right:310:[[WebComic/ColourWheel Using this image seemed a good idea...]]]]

* Creator/{{Sega}} of America had scheduled the Usefulnotes/SegaSaturn launch in North America for September 1995, until the Japanese headquarters ordered an early release to get an advantage over the Usefulnotes/PlayStation. So, during the first E3 in March Sega made the surprise announcement that 30,000 Saturns were already available. [[http://web.archive.org/web/20030615201046/http://www.gamespy.com/articles/june03/dumbestmoments/index21.shtml And then all the shortcomings piled up]]: the retailers left out of this release scheme were upset, some dropping Sega altogether; only six games were readily available for the console, with just two more titles in the following semester; and the simple announcement that the [=PlayStation=] would be $100 cheaper than the Saturn made people more eager to wait and purchase Sony's console instead.

* The mega-popular image hosting site Imgur instituted paid advertisements in June 2015. The first company to attempt it was Warner Brothers Records. The Creator/WarnerBrosRecords account had dropped to almost -60,000 reputation in less than a week. They made three whole posts before the account was reset due to this intense negative reception. This was mere days after the forced removal of NSFW comments (which in no way was related to the incoming advertisers, trust us), that sparked a mini-revolt by the community at large. Imgur reinstated NSFW comments as an option that was off by default.

* A humorous example: for the 2016 Olympics, to really get into the whole national spirit idea, the British Olympic committee decided to issue all their athletes matching luggage. Somehow, no one anticipated the rather obvious [[https://time.com/4464699/rio-2016-olympics-britain-baggage-claim/?xid=time_socialflow_facebook problem with this idea]] until it actually manifested.

** Of course, it being Jane, [[spoiler:[[SubvertedTrope none of this is true anyway]]; he's actually realized that Hightower was framed and is helping her escape.]]

* UsefulNotes/RichardNixon had one of the biggest LandslideElection victories in history, with a massive 96.7% of the electoral votes. He then got involved in one of the [[{{Scandalgate}} most infamous scandals in world history]], becoming the only President to resign, not to mention his administration bombed [[UsefulNotes/Cambodia]], in the worst air raid since UsefulNotes/WorldWarII. In history, he's remembered as one of the most despised Presidents, so much that when Noam Chomsky was mentioning war crimes committed by Presidents, he said that he could just ''skip Nixon''. Voters did '''not''' look well into his character.