"Urgh! Why must the end of a daydream taste so bad?!"
Most people, if not everyone, imagines things. However, sometimes somebody gets so caught up in a daydream that they start acting it out and doing things that only make sense in the context of what they're imagining, and that's what this trope is about.
Usually, this will go one of two ways: we, the audience, see the daydream, then the scene shifts back to reality and shows the character acting out the daydream (often being forced to stop daydreaming by someone pointing out their odd behavior, getting hurt by accident, or accidentally eating/kissing/drinking something that tastes bad), or the person gets asked why they're acting peculiar and they'll reply that they've been imagining something.
If the daydream involves them singing, it's a good bet that the singing will be a behavior they'll do in real life, and if it involves romance, they'll likely end up kissing or dancing with an inanimate object. They might also end up saying something related to the daydream out loud (for example, saying, "You're under arrest" out loud when imagining being a police officer).
This does not include dreaming while asleep. The reason for this is that they're less likely to actually think what's happening is real and they're still in control of their actions, so they're kind of forgetting it's not real, as opposed to being asleep, whereupon they're unconscious and they (usually) were always unaware that it wasn't real.
May overlap with Imagine Spot if the daydream is short and Daydream Surprise if we don't know going in that it's a daydream. Compare Marshmallow Dream, Talking in Your Sleep, Waking Non Sequitur, I Was Having Such a Nice Dream, and Sleepwalking for nighttime versions. Contrast Crashing Dreams (which can apply to sleeping dreams too) which is when reality starts to affect the fantasy rather than the other way round. May lead to Inner Thoughts, Outsider Puzzlement if others are around when a character starts acting out the daydream.
- In the Tintin book "Tintin and the Secret of the Unicorn", Captain Haddock is telling the story of his ancestor battling a pirate named Red Rackham and gets so caught up with the mental image that he starts acting out the fight, which greatly shocks Tintin and Snowy.
- In Horton Hears a Who!, Horton imagines himself as an anime action hero and does action poses in real life. He decides to stop when he accidentally kicks over a flower.
- In The Lorax, Ted imagines himself kissing his crush Audrey and his mother points out that he's kissing the cereal box, again.
- In one of the Winnie-the-Pooh movies, Pooh is very hungry and imagines a world where everything is made of honey. He then ends up eating mud because he'd been imagining eating honey.
- In a Mrs Pepperpot story, Mrs. Pepperpot is imagining herself as a detective and says, "Hands up!" to her husband.
- In the Big Time Rush episode "Big Time Christmas", Bitters watches It's a Wonderful Life with Katie and her mother, and wonders what the Palm Woods would be like without him. Katie starts to imagine an attractive hotel manager who throws dance parties in the lobbies, which makes her start dancing on the table. Bitters realizes what Katie's thinking about and walks away offended.
- In the Arthur episode "Bitzi's Breakup", Bitzi has the titular breakup with her boyfriend and wants to start dating again. Her son Buster is worried that her next boyfriend will be boring and imagines her dating a boring guy named Martin Spivack. Buster yells, "I hate Martin Spivack!", which confuses Arthur.
- Played for Laughs in the pilot episode of Rick and Morty. Morty has a dream about fondling his crush, Jessica's, breasts. When we return to the real world, we see Morty, fondling his math teacher, Mr. Goldenfold's, nipples. Mr. Goldenfold, subtlety hints at enjoying it by showing little interest in having Morty stop.
- In the Avatar: The Last Airbender episode "Nightmares and Daydreams", the sleep-deprived Aang imagines himself confessing his love to Katara and them making out. The real Katara is thoroughly confused by his behavior, which he excuses as having imagined himself "living underwater".
- Doug: The title character often gets lost in his daydreams and acts them out.
- Martha Speaks:
- In "Alice Twinkle Toes", Alice Boxwood wants to do ballet and starts imagining herself doing it. Then, she actually starts dancing, which confuses her friends.
- In "Martha's Adverb Adventure", the villain Otis Weaselgraft imagines himself being friends with Martha, then imagines himself eating a peach but snaps back into reality when he realizes he's eating a snowball.
- The Simpsons: In "The Devil Wears Nada", Mr. Burns announces that a new power plant supervisor will be needed to replace the one that retired, and Homer asks if the employees can supervise themselves. He, Lenny and Carl collectively imagine a scenario where they race each other in cars through the plant, ending with Homer and Carl crashing and blowing up in a mushroom cloud, prompting Lenny in reality to shout "I win!", which annoys Burns.
- Muttley tends to do this in his Magnificent Muttley segment when it transitions from daydream to reality, only for Dick Dastardly to abruptly awaken him.