Popular History

"The temptation is to have the characters keep reminding the audience what year it is. But characters in historical fiction don't know they're living in the past. They think they're living in the present. And they can't see into the future. So they shouldn't talk as if they're cribbing from history books about their own time. Dialog shouldn't contain many temporal signifiers. Which is to say you don't want to have characters who happen to be living in the 1970s saying things like: "Did you watch the Watergate hearings today? Can you believe Nixon taped all those conversations!" Or: "I bought the new Zepplin album today. Man, that Jimmy Page is a genius!" Or: "They're called Earth Shoes. They're supposed to be much better for your feet than regular shoes.""

- Lance Mannion

Popular History is when a show or movie set in a previous decade focuses on certain elements of the era's pop culture to an implausible degree, often mixing and matching things from different points in the decade and acting as if they existed at the same time (as in The Wedding Singer).

For instance, everyone in 1968 will be wearing tie-dye shirts, smoking pot and going to see the Stones or The Doors while protesting The Vietnam War. Everyone in 1977 will either be wearing platform shoes, a polyester leisure suit, an afro, and will be going to the disco, or wearing torn jeans, Doc Martens or converse, ripped shirt, leather Jacket and going to pogo to the Clash or the Pistols. Everyone in 1985 will sport Miami Vice-type pastel clothes and mullet hairstyles if they are men, big hair, lots of make-up and power suits if they are women, and early Madonna/Debbie Gibson-type outfits if they are teenage girls. Also applies to cars in the street; they will all be models from the year portrayed, as if nobody has kept a car they bought in a previous decade. Also compare the amount of smoking in movies from the '50s and before with that in modern movies set then.

This is especially painful when you consider that the writers generally lived through the era being depicted (meaning Did Not Do the Research doesn't - or shouldn't - apply).

Sometimes, a movie about the period that's considered "not enough" will hit a lot closer to home. The early and even mid-1980s had a lot of late '70s styles hanging around. The perm or wavy haircut was very common around the mid-1980s (the Cobra Kai guys all had this cut in The Karate Kid), but you never see it being used when people recreate the '80s—probably because it "doesn't look '80s enough".

None of this is to imply that nobody in a past era was conscious of the time they were living in or historically self-aware; indeed, cultural critics and pundits have often made a living in the field of attempting to be prescient (and sometimes they have succeeded!). This trope is for instances when an "average person" who can't possibly predict future nostalgia is depicted having an outlandish amount of Genre Savviness.

For a good depiction of a time period, one should look at the TV shows, books, plays and movies that were made during that period. Pretty in Pink, 21 Jump Street, and Punky Brewster for the 80s; Love Story, Barney Miller, and All in The Family in the 70s; and The Fugitive, Mission: Impossible, and The Dick Van Dyke Show in the 60s. However, beware of a show that tried to be Totally Radical.

Nothing but Hits is a subset of this trope. See also: Politically-Correct History; Nostalgia Filter; "Mister Sandman" Sequence. Compare: Anachronism Stew; Frozen in Time. For this trope in reverse, see Present Day Past. When a work actually made during the relevant time period appears to fit this trope, it's an Unintentional Period Piece.

Film

 * Played with in Back to The Future Part II in which a cafe from the year 2015 is dedicated to the Popular History of the then-contemporary 1980s. (Of course, the irony nowadays is that the rest of the 2015 version of Hill Valley looks just as '80s as the cafe.)
 * Surprisingly, with 2015 here Cafe '80s is very accurate to stereotypical modern Popular History views of the period. In a way this makes it both a straight version and a subversion as they were consciously invoking the trope about their own era, but getting it right as if it actually was from the future.
 * Amazingly, the trilogy as a whole averted this with their own respective versions of 1955 and 1885, like using cars from the late 1940s in 1955, and lampshading the '50s idea of cowboy garb that Marty is given prior to coming to 1885. (It's decorated with tiny atoms. Good luck explaining those to folks who wash their underwear in the river.)
 * The cowboy one goes so far as to have him make a Clint Eastwood crack, which confuses everyone. There's a poster on the wall of this scene advertising Revenge of the Creature, Eastwood's first film (it's a bit part as a lab assistant).
 * The entirety of Indiana Jones and the Kingdom of the Crystal Skull. It looked like they were dredging up every single possible period detail relating to the 1950s.
 * Forrest Gump had plenty of this.
 * Done oddly in the movie version of Mamma Mia!, where Donna flashes back to her three old boyfriends in their prime. Apparently they each wore clothes from a different decade, even though these flashbacks were supposed to take place in the 1980s. Watch out for Pierce Brosnan as a hold-over hippy...
 * We are talking about a movie that has cars, dresses and culture from the 40's-50's Greece in the present day! I mean...look at the cars!
 * In The Naked Gun 33 1/3, Drebin recognizes a woman as a suspect in an unsolved murder back in the 70's. Cue Flash Back of the murder: It happened in a disco, and Drebin, Hocker, and Nordberg are all decked out in leisure suits, gold chains, and huge afros.
 * It gets even more ridiculous when you realize that the woman, who is about in her late twenties in the present day (1994), would have been a teenager when the disco era ended, but in the flashback is as... er... "buoyant" as ever.
 * Rumor Has It... gets pretty annoying with it, but the worst example is probably prominently showing during a party scene three men with no bearing at all on the plot discussing how there's this thing called Google that's gonna be a huge hit.
 * The Time Scout series mostly averts this. The authors go to some effort to make sure they avoid the worst stereotypes and be historically accurate. How well they succeed depends on your own knowledge.

Live Action TV

 * Life On Mars and Ashes to Ashes are good examples of this. Ashes To Ashes mixes very early eighties fashions (Ray's The Professionals look) with yuppies wearing mid-to-late Eighties Miami Vice gear. Both series also play with this trope, as it's revealed that
 * The short-lived sitcom Do Over took place in 1980, but had certain elements as far as 1985. Furthermore a character in the first episode said it was the year 1981, which just made the confusion even worse.
 * This was subverted and lampshaded in an episode where the main character (a man reliving his high school years) dresses up as a ghostbuster for Halloween. It isn't until he shows it to his dumbfounded friends that he remembers that the movie won't come out for another four years.
 * Played with in How I Met Your Mother: Robin was a teen idol in Canada, and the film clip to her song Let's Go to the Mall is stereotypically eighties, but it was made during the early nineties. This is played more as a joke that Canada is behind the times, though.
 * Cold Case frequently does this when returning to a flashback with the music playing during the era that's discussed. Pop culture references are also frequent if they happened around that decade.
 * Gossip Girl: Lily has a flash back to the eighties, and it is complete with all the associated stereotypes.
 * Sort of averted in Everybody Hates Chris. Most of the kids wear clothes that are generally in style (jeans and a t-shirt) and Rochelle has a seventies hairstyle in the early episodes.
 * Averted in Freaks and Geeks: None of the characters wear the standard '80s attire as it is only 1980, and disco is popular (much to their annoyance).
 * Averted in Mad Men: While set in the 60's, the attitude and style of the main characters still reflect the previous decade, with many of the older characters (like Duck and Roger) reflecting the decade before that one.

Western Animation

 * Futurama: While trying to look inconspicuous in 1947 Roswell, Leela wears a poodle skirt and the Professor wears a zoot suit (though they did pretty well considering they were from a thousand years in the future, and Earth and its records were devastated by wars several times during that period). In the second episode, this is slightly lampshaded when a 31st century attraction does this to the entire 20th century. "Let's disco dance, Hammurabi!"
 * DY-NO-MITE!
 * The Roswell episode shows a lot of the failings of the 31st century characters' knowledge of history. The Professor and Leela don't realize that microwaves haven't been invented yet; when they go to a diner, they first order Soylent Green, then overcompensate by ordering "mutton and a stein of mead."