Sometimes, even films considered to be timeless classics can contain a line or two that aren't quite as timeless, and that's certainly the case with specific, dated lines of dialogue in '80s movies have been remade.

From celebrity cameos, to callbacks to other films, to references to now-obscure products, these lines can take many different forms. Screenwriters must try their best to walk the fine line between keeping their dialogue culturally relevant, but not so dependent on pop culture that it is doomed to fade into obscurity. Now, even though modern audiences may not understand all of these references in '80s movies, one can still appreciate them for the joy they once brought.

10 Pepsi Free

Back To The Future (1985)

Beloved rascal Marty McFly is thoroughly out of his element when he travels thirty years into the past in the classic 80s film, Back to the Future. Finding himself at a diner, Marty absentmindedly orders a Pepsi Free. Lou, the man working behind the counter, replies in a slightly irritated voice, "If you want a Pepsi, pal, you're gonna pay for it!"

This comedic exchange is a play on words surrounding Pepsi Free, the then-popular soft drink. Unfortunately, Pepsi Free was discontinued in 1987, just two years after the release of Back to the Future. It was later replaced with a product simply known as Caffeine-Free Pepsi.

Sadly, this means that this cleverly worded exchange is now lost on modern audiences, as most first-time viewers are now unfamiliar with the decades-old soft drink. Fortunately, the majority of Back to the Future still holds up very well, so one outdated exchange hardly impacts the reception of the film as a whole.

9 "You Mean J.R., Just Like The TV Show?"

Raising Arizona (1987)

The Coen Brothers' 1987 comedy, Raising Arizona, is jam-packed with dialogue bound to get audiences laughing. Unfortunately, not every line has withstood the age of time. In one exchange, H.I. (played by Nicolas Cage) mentions that he calls his newly-acquired baby "Junior." H.I.'s friend, Evelle (played by William Forsythe), quickly chimes in, "You mean J.R.? Like the TV show?"

At the time the film was released, most viewers would have caught the humorous nod to Dallas, the popular TV drama which began in 1978, and ran all through the 80s. Evelle's question is a direct reference to J.R. Ewing, one of the prominent characters on the show. Unfortunately, Dallas reached its end in 1991. While the show was extremely popular at the time, it is far less likely that today's audiences would have seen it.

8 Sleeping With Prince Valium

Beetlejuice (1988)

Tim Burton's 1988 comedy/horror film, Beetlejuice, is not one to shy away from references to other movies. However, while its references to films like The Wizard of Oz and The Exorcist are still easy for modern audiences to understand, others don't hold up quite as well. A key example would be when Lydia (played by Winona Ryder) remarks, "You can't scare her, she's sleeping with Prince Valium tonight."

Though today's audiences may understand the tie-in to Valium, a drug designed to relax one's nervous system, it is less likely that they'll catch the specific reference to the comedy film, Spaceballs, which was released just one year before. Even viewers who have seen Spaceballs may not pick up on the reference, as Prince Valium was only a minor character. The Beetlejuice line may have been able to capitalize on the film's popularity immediately following its release, but it's bound to go over viewers' heads today.

7 "Does Barry Manilow Know That You Raid His Wardrobe?"

The Breakfast Club (1985)

Unfortunately, there's a significant number of dialogue and story decisions in The Breakfast Club that have not aged particularly well. This includes one-liners like this one, when Bender asks Principal Vernon, "Does Barry Manilow know that you raid his wardrobe?" This question alone is enough to land Bender a spot in yet another Saturday detention.

While the line was certainly a crowd-pleaser when the film was released, it loses a bit of its punch as audiences become decreasingly familiar with Barry Manilow. The "Copacabana" singer may have been a sensation in the 70s and 80s, but it's doubtful that younger audiences today would know what he looked like. That means they must either take the time to look up what was so outrageous about his wardrobe, or simply shrug off the joke.

6 "You Sounded Like Dirty Harry Just Then"

Ferris Bueller's Day Off (1986)

Although Ferris Bueller's Day Off still remains popular (especially among students), not all of its dialogue has proven to be as timeless as the rest of the film. A prime example of this comes during a brief scene featuring the overbearing principal, Ed Rooney (played by Jeffrey Jones), and his secretary, Grace (played by Edie McClurg).

The line is a reference to Clint Eastwood's titular character in the Dirty Harry film series.

After Rooney angrily declares that Ferris Bueller should not be seen as a role model, Grace is visibly impressed, commenting, "Oh, Ed. You sounded like Dirty Harry just then." The line is a reference to Clint Eastwood's titular character in the Dirty Harry film series. The character is a stone-cold antihero, willing to pursue justice at any cost.

Sadly, the humorous comparison between the uptight school worker and the rogue police officer doesn't land quite as successfully with modern audiences. Even if they have heard of the Dirty Harry films, it is decreasingly likely that they know the character well enough to understand just how absurd the comparison truly is.

5 The Kevin Bacon Cameo

Planes, Trains, and Automobiles (1987)

Planes, Trains, and Automobiles, the 1987 buddy comedy by John Hughes, has remained a film watched every year for countless viewers around the globe. However, while its charming story and witty dialogue have held up over time, one early scene does not pack the same punch that it once did. Soon after the audience is introduced to Steve Martin's character, Neil Page, a chaotic scene occurs in which Neil must race an unknown man to claim a taxi first.

Though the character never speaks (and is credited only as "Taxi Racer"), he is played by none other than Kevin Bacon. The entire scene is a reference to the opening of the 1986 film, Quicksilver, which starred Bacon. Unlike Planes, Trains, and Automobiles, Quicksilver has not managed to maintain the same level of popularity over the years.

Because of this, the entire scene goes over the heads of most modern viewers. It is less likely that audiences today even recognize the Footloose star at all, as many of his most popular films were from the 80s and 90s. Regardless, the scene does still manage to set up the central conflict of the film, so it remains a necessary moment.

4 "Here's Johnny!"

The Shining (1980)

Stanley Kubrick's 1980 film, The Shining, remains one of the most well-known horror movies in existence, even nearly 45 years after its initial release. Interestingly, the most frequently quoted line from the film is actually a reference that many current fans don't even recognize. In a pivotal scene, Jack Nicholson's character, Jack Torrance, violently uses an axe to break through the door of the bathroom where his wife is hiding.

Nicholson's iteration of the line in The Shining has managed to maintain popularity in its own right.

At one point, Jack presses his face through a narrow hole in the door, and, with an eerie smile, exclaims, "Here's Johnny!" Though the scene has remained a fan-favorite for decades, many of today's viewers don't even realize that the line is a reference to The Tonight Show Starring Johnny Carson. "Here's Johnny" was originally Ed McMahon's famous catchphrase which he would use when introducing the talk show's host.

Carson's run as host of the popular late-night show came to an end in 1992, meaning audiences would no longer be hearing the line every night. Despite this, Nicholson's iteration of the line in The Shining has managed to maintain popularity in its own right.

3 "Where's the Beef?"

The Muppets Take Manhattan (1984)

Jim Henson's beloved Muppets are no stranger to including pop culture references in their movies and TV shows, and The Muppets Take Manhattan is no exception. In one scene from the 1984 film, Rizzo the Rat, while working in Pete's Luncheonette, serves a customer a cheeseburger. Upon being informed that the "cheeseburger" was only bread and cheese, Rizzo turns toward the chef and yells, "Where's the beef?"

Audiences who lived in the 80s will recognize this as a nod to the Wendy's commercial that quickly became a phenomenon. In the commercial, an elderly customer at an unnamed fast food restaurant is given a burger with a massive bun, but only a tiny patty.

She proceeds to emphatically exclaim, "Where's the beef?" The line quickly became a catchphrase not just for Wendy's, but as a general statement of one's frustration with being given an underwhelming product. Although the slogan has been revived a couple of times, it is not nearly as well-known as it once was.

2 Kareem Abdul-Jabbar

Airplane! (1980)

Being a spoof of various disaster movies of the 70s, Airplane! is densely packed with pop culture references. One of the most prominent references, though, is actually to a famous athlete of the era. In the film, NBA legend Kareem Abdul-Jabbar makes an appearance as a man claiming to be Roger Murdock, the plane's co-pilot.

A child on the plane eventually recognizes him as the basketball star, causing Abdul-Jabbar to snap, exclaiming, "I'm out there busting my buns every night! Tell your old man to drag Walton and Lanier up and down the court for 48 minutes!" Abdul-Jabbar played in the NBA for twenty seasons, ending his career in 1989.

The other players he references in the scene are Bill Walton and Bob Lanier, who also played basketball professionally until 1988 and 1984, respectively. While fans of the NBA would be familiar with all of these players, it is less likely that their names would be as well-known by society as a whole nowadays. Modern audiences can infer that these were all-star athletes of their era, but the jokes don't land as well without having actually seen them play.

1 "That's My Name, Don't Wear It Out."

Pee-wee's Big Adventure (1985)

It's no secret that Pee-wee Herman, played by the late, great Paul Reubens, isn't exactly the coolest character to grace the screen. However, during an exchange with the bully, Francis, in Pee-wee's Big Adventure, the character has a sudden boost of confidence as he rebuffs Francis for trying to take his beloved bicycle.

After the frustrated bully yells his name, Pee-wee snidely replies, "That's my name, don't wear it out." While the expression has become widely used as a form of playground retort, Pee-wee's cocky delivery is an homage to the 1978 film, Grease.

In the hit musical, Danny Zuko (played by John Travolta) says the line with a similar swagger as he attempts to make his friends believe that he is the coolest guy around. Although Grease certainly had a successful run, it is far less likely that modern audiences would recognize the callback to this one particular line.