There's one exchange between Marty and Doc that doesn't seem very significant, but according to this fan theory, it's the key to the ending of 'Back to the Future.'

MOVIES
The words used in the Harry Potter books and movies are playable in a new version of Scrabble—and they can even earn you bonus points.
All sequels are not created equal. Over the course of more than 90 Oscar ceremonies, only eight sequels have ever earned a nod for the night's top honor.
The Oscar-winning director may have fake-directed the fake-version of 'Aquaman' in 'Entourage,' but a lack of reality would never have allowed him to do it in real life.
Winning an Oscar is, for most people, a once-in-a-lifetime achievement ... So you'd think their owners would be a little more careful with them.
"I know I’m not the last Harry Potter I’m gonna see in my lifetime," said Daniel Radcliffe about the inevitability of a reboot.
"I wrote the Hermione/Ron relationship as a form of wish fulfillment," the author said, before admitting that Harry and Hermione made more sense as a couple.
For more than 90 years, the Academy of Motion Picture Arts and Sciences has rewarded excellence on the big screen—and they've seen plenty of historic firsts over the decades.
One Redditor crunched the numbers to figure out just how long it would take for Doctor Strange to watch more than 14 million possible outcomes in the Avengers's fight against Thanos—and how he might be able to use that time to their advantage.
Had things worked out differently, the ominous voice of Darth Vader could have sounded a lot like Charles Foster Kane's.
Choosing a favorite Harry Potter movie kind of feels like picking a favorite child—you say you can’t pick favorites, but deep down you do. Leading man Daniel Radcliffe is no exception. Harry himself recently revealed his favorite of the franchise—and the
What's in a name? A lot if you're planning to make a mark in Hollywood. Which is why some of your favorite actors may not have been born with the name you know them by now.
Once again, Valentine’s Day is upon us. Why not spend the day binge-watching some of your favorite romantic comedies? Here are 40 fun facts to get you started.
'Avengers: Infinity War,' which is just 15 minutes shorter than 'The Godfather,' currently holds the record for longest MCU movie. Could 'Endgame' stray into 'The Godfather: Part II' runtime territory?
Tom Cruise could've been a contender.
In the nearly 30 years since the release of 'Groundhog Day,' fans have spent plenty of time and precious web bandwidth attempting to decode the alleged layers that exist just below the surface.
It's possible, but we're not betting on it.
The reason for it was practical, except in poor Emma Watson's case.