Did you know the actor Arnold Schwarzenegger once appeared in a movie called The Terminator, and that he said the line "I'll be back"? If you're hoping to watch any Arnie movie, past, present, or future, be prepared for that line return to you again and again, like some out-of-control boomerang. Arnold says "I'll be back" or some variation of it in almost every post-Terminator movie he's been in, including the lesser-seen whimsical 2007 comedy Mr. Schwarzenegger Goes to the California Governor's House (via New York Times). By the time it resurfaced in The Expendables III, the line was as old and tired as the Expendables themselves.
Arnie might have been an early adopter of the needless callback Easter egg, but he certainly wasn't the last. Moving into the modern era, we're in danger of getting swamped beneath a tidal wave of half-remembered quotes that, just like marriages, go from "awesome" to "depressing" the more times you experience them.
The chief offenders in the court of unnecessary callbacks might well be the new Star Wars movies. As Slate exhaustively detailed, much of the dialogue in The Force Awakens amounts to "insert classic Star Wars reference here." The Last Jedi was a little more restrained, but characters still had bad feelings about this, and other callbacks (via Den of Geek). Hey, it's easier than having to write a whole new script from scratch.
