It Seemed Like a Good Idea At the Time

Someone does something that puts them, or the people around them in a bad or unpleasant situation. Hindsight reveals that although they had good intentions, their actions were not in their best interests.

If questioned about why they did it, they'll often respond with the reason for everything that has ever been done by anyone at any time and any place: "It seemed like a good idea at the time!".

This is also used sometimes as an explanation for Chaotic Neutral or Chaotic Stupid actions. Contrast I Did What I Had to Do, which does the same as in this case, but for Lawful Neutral or Lawful Stupid actions and their moral, rather than strategical, consequences.

Compare the situational trope, Nice Job Breaking It, Hero.

Comics

 * This explanation gets used a lot in Nodwick. Especially by Yeagar. Who, to be fair, has the wisdom of a lemming.

Films -- Live-Action
"Jesse James: A war against the railroad... what the hell was I thinking? Frank: Well, I'm sure it seemed like a good idea at the time."
 * American Outlaws

"Mason Verger: The good doctor approached me with a piece of broken mirror and said...[Flashback: Lecter is holding a shard of broken glass] Hannibal Lecter: Try peeling off your face... Mason Verger: ...and feeding it to the dogs. [Flashback: Verger peels his face off.] Well, it seemed like a good idea at the time."
 * Hannibal

"Dr. Dix: I hate fishin'. Chief Jesse Stone: So do I. Dr. Dix: So why'd you suggest it? Chief Jesse Stone': Seemed like a good idea at the time, doesn't cost me anything."
 * Jesse Stone: No Remorse. Jesse Stone suggests Dr. Dix take up fishing.

"Lucy McClane: Daddy, you're out of your mind. John McClane: What're you talkin' about? Lucy McClane: You shot yourself! John McClane: [groaning] It seemed like a good idea at the time."
 * The 1975 comedy film called, It Seemed Like a Good Idea at the Time, starring Stephanie Powers and John Candy.
 * Live Free or Die Hard

"Calvera: What I don't understand is why a man like you took the job in the first place, hmm? Why, huh? Chris: I wonder myself. Calvera: No, come on, come on, tell me why. Vin: It's like a fellow I once knew in El Paso. One day, he just took all his clothes off and jumped in a mess of cactus. I asked him that same question, "Why?" Calvera: And? Vin: He said, "It seemed to be a good idea at the time.""
 * The Magnificent Seven:

"Evelyn: By the way, why did you kiss me? Rick: I don't know. I was about to be hanged. It seemed like a good idea at the time."
 * The Mummy 1999

"Jerry Conlaine: But you could've left! Why'd you stay up here all these years? Del Knox: Seemed like a good idea at the time. Know what I mean, kid?"
 * In the Mystery Science Theater 3000 movie, Crow attempts to escape the Satellite of Love by digging a tunnel through space. When asked why he decided to bore a hole through the hull of the ship, he responds, "I calculated the odds of this working vs the odds that I was doing something incredibly stupid and... I went ahead anyway."
 * Without a Paddle. Del Knox has spent 30 years in a cabin after partnering with D.B. Cooper in his famous skyjacking.

"Chris Kelvin: Why did you kill yourself? Gibarian: It seemed like a good idea at the time, now I think I made a mistake."
 * Solaris

Literature

 * The Hitchhiker's Guide to the Galaxy: Everything Zaphod Beeblebrox ever does, except when caught up in a Plan related to finding out who really rules the universe in later volumes.
 * In the novel Knight Life by Peter David, Merlin says any question can be answered by one of three statements: "Everybody has to be somewhere," "God told me to do it," and "It seemed like a good idea at the time."
 * In Oryx and Crake, where pigs are spliced with human DNA in order to create ultra-large pigs who grow multiple human organs that are used for transplants. Some of them even have some human brain tissue, which makes them viciously intelligent. Of course, it seemed like a good idea at the time.
 * Similarly to the Oryx and Crake example, in the Revelation Space universe an intelligent species of "hyperpigs" exists due to genetic manipulations conducted to provide transplant materials. While things are rocky for a long while, a hyperpig ends up being vital to saving all humans and hyperpigs from the Inhibitors.
 * Michael's bright idea in the Knight and Rogue Series to be marked as a permamently unredeemable criminal, unprotected by laws, immediatly judged harshly by all, rather than bring in a woman who used him as an unwilling test subject for trial and agree to work for his brother, who states that he doesn't even want to employ Michael if his younger brother hates the idea of working for him so much. He insists this will give him the freedom he wants... right up until people cheat him out of hard earned money for being a crook and he can't take the issue up with the law.
 * Any of Chris's antics during his college career in The Pale King.
 * In the Discworld series, Nanny Ogg's primary method of functioning is explicitly described as, "Nanny's philosophy of life was to do what seemed like a good idea at the time, and to do it as hard as possible. It had never let her down."
 * A nonfiction book by Bill Fawcett cataloging such events in Real Life uses the trope as its title.

Live Action Television
"Remy Baudouin: I can't believe you actually did that. You could have ended up in front of a firing squad! Indiana Jones: They'll never figure it out. Remy Baudouin: But still, you lost your courier's job, and you put yourself back in the mud. You're crazy! Indiana Jones: It seemed like a good idea at the time. Some men got to live another day."
 * The Adventures of Young Indiana Jones episode "Demons of Deception" ("Verdun" and "Paris")

"Lily van der Woodsen: Really, Rufus, what were you thinking? You threw her a surprise birthday party and had her face painted on a cake with a tiara? Rufus Humphrey: It seemed like a good idea at the time. Lily van der Woodsen: So did flannel and acid wash-jeans, but they weren't flattering either."
 * The producers of The Amazing Race have been quoted as saying this about the Family Edition.
 * On Attack of the Show, they tested the Sham Wow! and the Zorbees, and used substances such as vomit. Kevin nearly threw up on camera.
 * And then they tested the Slap Chop on sheep eyes...
 * Comes up in almost each plan by John in Farscape.
 * Gossip Girl episode "All About My Brother"

"Clark Kent: Glasses, secret identity... seemed like a good idea at the time."
 * Lois & Clark: The New Adventures of Superman episode "Tempus Fugitive"

"Quark: I still don't understand why you'd want to come here in the first place. Zek: Simple, really. I came to find new financial opportunities for the Ferengi people. Rom: In the alternate universe? Zek: Well, it seemed like a good idea at the time."
 * On an episode of Night Court, Mac’s bigoted grandfather can’t accept that his grandson has married an Asian woman. So Harry orders his grandfather arrested and locks him up in the same cell with Mac’s wife, so the two of them can get to know each other better. Mac is aghast when he finds out, and a crestfallen Harry gives the trope name word-for-word as his defense. Mac responds, “Well, sir, I’m sure human sacrifice seemed like a good idea at the time!”
 * Star Trek: Deep Space Nine episode "The Emperor's New Cloak".

"Sisko: In other words, you saw which way the wind was blowing and switched sides. Dukat: It seemed like a good idea at the time."
 * The Stock Phrase 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.

"Terry Lee: Good timing, Major. Major Ellis: Oh, it was quite simple. All I had to do was follow the baskets you chaps so thoughtfully pushed off the truck. Terry Lee: It seemed like a good idea at the time."
 * Terry and the Pirates episode "Deadly Species" (1952)

"Bubbles: You're not really marrying Lahey's ex-wife are ya? [snip] Ricky: Look Julian, I was baked out of my mind, it seemed like a good idea at the time alright?"
 * Trailer Park Boys episode "Propane, Propane"

""Mr. President, are we to understand that she just walked right into your office and started...well, you know." "Seemed like a good idea at the time!""
 * One stand-up comedian says that this is the reason why men do so many stupid and idiotic things, because guys aren't thinking about the past or the future and are only concerned with having a good time right now. He uses Bill Clinton as an example, and claims Bill would have gotten off scott free if he had just told the truth.

"Unnamed child: You already pre-paid us. For the whole month. (holds a wad of cash up to Carly and Freddie) Carly: (to Freddie, who looks at her weirded out) ...It seemed like a good idea at the time."
 * iCarly episode "iSell Penny Tees":

Music

 * The song A Good Idea At the Time by OK Go both expresses Sympathy for the Devil and is an explicit homage to the Rolling Stones song Sympathy for the Devil, portraying Lucifer as simply a guy after a good time who keeps winding up causing horrific situations throughout history, usually because of this trope and the consumption of ludicrous amounts of booze.

Radio Show

 * True to its tendency of turning sayings into titles, This American Life has done an episode (#306) that's flat out titled "Seemed Like a Good Idea at the Time."

Western Animation

 * Milked for all its comedic worth in Family Guy. Adam West rolls around in nuclear waste in order to gain superpowers—and gets lymphoma. The doctor who he explains this to is taking this all in, and concludes that Adam West is an idiot—much as someone would do were this same feat attempted in Real Life. The catch? Earlier in the story, the Griffins had gained superpowers in a manner quite similar, and Adam West's rolling around in the waste was part of a desperate plot to put a stop to their evil dominion over the town. Of course, he still succeeds—the Griffins feel extremely guilty realizing that Adam West got lymphoma just because they were using their superpowers to be petty jerks.
 * By technicality that would also make this moment an Unintentional Backup Plan.
 * The Amazing Chan and The Chan Clan episode "The Gypsy Caper". Suzie, Alan, Anne and Tom are exhausted, Tom spots a hive and suggests they partake of the honey as a natural energy source. Unfortunately, the bees aren't too thrilled about that and the group ends up getting a second wind by fleeing and diving into a lake.
 * In Jackie Chan Adventures, Jade destroys Shendu after they beat him at the end of season 1. Unfortunately this allows other forms of evil beings to come forth, since the world NEEDS a balance of good and evil. The only reason it seems things float towards the good side of things is because said evil is sealed, NOT destroyed.
 * Another smaller version is when Jackie destroys the talismans. He had hoped that their power would be destroyed and would end people misusing their powers, but unfortunately their powers can't be destroyed only their hosts (which were the talismans at the time) can. So now their powers seek out new hosts and he inadvertently started the talisman hunt all over again.
 * In Drawn Together episode "Breakfast Food Killer", that hiding the UCP codes up his butt seemed like a good idea at the time. Though he didn't really have any other place to hide them.
 * In the episode of the Nickelodeon cartoon Rugrats entitled, "Chuckie is Rich", Drew stupidly invests all of Chaz's new money into some stupid invention. He uses this as his excuse.

Webcomics

 * In DMFA, the cubi race are mentioned to be the kings of this, due to their emotion reading talents making them very emotional.

Web Original
" So, what did you do? Aw, man, it seemed like such a good idea at the time!"
 * In the Chakona Space 'verse, chakats are mentioned to be highly susceptible to this.
 * Red vs. Blue, in episode 52 Have We Met?:

"Doctor: Your mom's insurance cut her off, so we've replaced her IV with a 2 liter of Sprite. Kurama: Why would you do such a thing? Doctor: Uh, it seemed like a... not good, but funny idea at the time..."
 * In Yu Yu Hakusho and the Magical Mirror, an Abridged Parody:

Video Games

 * In Portal 2 you're given the opportunity to remove Big Bad G La DOS' control over the facility and replace her with Wheatley, a cheery, kindhearted robot that's done nothing but help you. Seems like a great idea, right?

Real Life

 * Most of history can be fit under this, especially the really catastrophic parts.
 * So can the really funny parts too.