You meet yourself somehow, through Time Travel, dimension-hopping, cloning, or some even more exotic form of Applied Phlebotinum. Inevitably, if you spend enough time in the same room as yourself, the two of you will end up speaking in unison.
The implication isn't usually that there's any kind of mystical connection between the different versions of you. It's just that whatever you're saying is so characteristic of you that any possible version of you would have said it at that time.
- A Chance Meeting Of Two Moons: Luna and Artemis do this when they first meet, and it happens again in chapter 5. Twilight and Dusk Shine later have the same thing happen when they meet. Celestia and Solaris also fall into it at one point, but only when they're flustered.
- A bizarre version occurs in Bill & Ted's Bogus Journey; the two aren't the same person, but they're so close in personality they might as well be; so when they split off to propose to the princesses, they read out the same speech, changing only the basic metaphor (one of them uses ocean life, the other forest; they even both have a 'no, that's fresh water' / 'no, that's the desert' moment in unison.
Present B&T: 'If you're really us, what number are we thinking of?Future B&T, in unison: 'Sixty nine, dudes!'
- There's also the point where present Bill and Ted meet future Bill and Ted (or the same scene later in the film where present Bill and Ted are now the future Bill and Ted meeting past Bill and Ted):
- Similar to the above Bill & Ted trope, but for a blink-and-you'll-miss-it Not So Different: In Treasure Planet, when Jim is put in Silver's care, both pinch the bridge of their respective noses at the exact same time, then look up with the same expression.
- The 6th Day: Adam Gibson teams up with his clone. They're mixing up some thermite and one of them decides to test-burn some of it. They watch as it burns through the table.
Adam Gibson and Adam Gibson: Cool.
- The main character of The Probability Broach by L. Neil Smith does it on one occasion, when in the company of his alter ego from another timeline.
- In Star Trek: Department of Temporal Investigations: Watching the Clock, President Bacco is temporarily duplicated (long story). The two presidents respond to a compliment with a simultaneous "Oh, please!" Amusingly, they also snark at each other for making the exact sort of grumpy, sarcastic comments that Bacco always makes.
- A variant in John W. Campbell's story "The Brain Stealers of Mars": Ted Penton and Rod Blake encounter shapeshifting aliens who impersonate them, and they have to spot the imposters; because the aliens can read minds, they can flawlessly imitate what Penton or Blake would say. It's not long before all twelve Pentons start speaking and acting in unison. Blake, on the other hand, is more uncertain, and the Blakes argue with and contradict one another despite all having access to the same mind.
- In the Star Trek: Deep Space Nine episode "Visionary", O'Brien meets himself from five hours in the future. At one point they chorus "I hate temporal mechanics."
- The Dollhouse episode "The Left Hand" sees Topher downloading a second copy of himself into Victor.
Adelle: Finding him obstinate, are we?Topher and Victor: Yes! (pause) This is so weird.
- Stargate SG-1:
- In "Tin Man", O'Neill and his robot duplicate get to chorus "For cryin' out loud!"
- In "Fragile Balance", O'Neill gets cloned; his clone is a 15-year-old boy. When they meet up at the end of the episode and interrogate the alien who did it, they start answering him in unison. Eventually, the original O'Neill gets annoyed and tells his clone to knock it off.
- In the Buffy the Vampire Slayer episode "The Replacement", Xander gets split into two beings. When they meet at the end just before being rejoined they have a tendency to speak together.
Buffy: What if it doesn't work?
Xanders: Kill us both, Spock!
Willow: They're kind of the same now.
Giles: Yes, he's clearly a bad influence on himself.
- Done with actions in Heroes, such as Hiro being in the background of Young!Hiro as both push up their glasses at the same time in the same way.
- Doctor Who:
- When Mickey and his parallel-universe counterpart Rickey are running away from Cybermen in "The Age of Steel", they stop to catch their breath and each go off in their own panicked monologue, culminating in a unison recitation of "They know where we are!"
- Done again in Series 6, with The 11th Doctor and "11.5", a clone created from sentient goo. They both have all the same memories and thought processes, leading to them almost always finishing the other one's sentences and saying the same thing at the same time. They actually don't mind, but it annoys Amy.
- Played for drama in Farscape, when Crichton gets twinned, and the two talk and think so alike that when they resort to RockPaperScissors to decide which one is real, they end up spending several hours tied, before giving up. After one of them dies and sends the other a holographic message, it ends with the hologram and living one playing RockPaperScissors and ending up tied again.
- In the Red Dwarf episode "The Inquisitor", Lister gets replaced by an alternative version of himself who never got to exist. When they meet each other, the original Lister is in the middle of trying to convince Rimmer of who he is, and the two end up chorusing "Rimmer, for smeg's sake!"
- Fringe: Astrid and Alt!Astrid meet and, though very different in some ways, find themselves frustratedly making the same exclamations four times in a row
- Chrono Cross: When you hop from Serge's "Home" dimension to "Another," certain of your party members can meet their alternate counterparts, and this is an occasional result.
- In Basic Instructions, Scott meets himself (without a precise explanation of how), and soon the two of them unintentionally (and to their mutual annoyance) mirror each other.
- In the Animated Adaptation of Men in Black, when Jay first sees his quick clone, they say in unison "He's stunning!".
- Futurama has a variant when Leela encounters her double; they're not actually simultaneous, but...
Robot Leela: I have to go. This is just too freaky! (storms out)
Fry: Please don't get upset, Leela. She's nothing like you!
Leela: I have to go. This is just too freaky! (storms out)
- There was also their failure to solve a problem with perfectly symmetrical violence— simultaneous flying kicks to each other's faces.
- In Phineas and Ferb The Movie: Across the 2nd Dimension, this happens three times between Dr. Doofenshmirtz and his more evil double in the other dimension. Each time, Doofenshmirtz-1 lampshades it by shouting "Jinx!" and claiming that Doofenshmirtz-2 owes him a soda.