People hate plot holes in movies. At least, that's what they'll tell you. But sometimes, if a movie is awesome enough, people will overlook even the most retarded gaps in reason and logic.
At least, until some asshole on the Internet points them out and makes a big list of them. Enjoy:
8Back to the Future
Marty McFly goes back in time, helps his parents get together, invents rock and roll...
...and everyone promptly forgets he was ever there the minute he leaves.
Nobody notices that a famous clothing brand is later named after him, nobody notices that Chuck Berry releases a song that sounds pretty similar to the one he played at the big dance, and most importantly, nobody bats an eyelid when his Mom has a kid who looks exactly like him.
Now we don't claim to know exactly what first enters the mind of a married man when his wife births a child who looks identical to their old high school boyfriend, but we're guessing it's not "time travel conspiracy." Old George was either the most oblivious, forgiving man on earth, or there were some secret resentment beatings in the McFly household.
Even more disturbing, what must his Mom have thought? The only explanation we can see making sense from her point of view is that Marty was Satan (he did invent rock and roll after all) and the whole thing's some kind of demon spawn Rosemary's Baby type deal. And no one should ever be in a position where the most plausible explanation for their situation implies that they fucked Satan.
This was the most sinister looking picture of Michael J Fox we could find.
Plus, think how chilling Marty's final remark on stage becomes given this context: "I guess you're not ready for that yet... but your kids are gonna love it."
Tom Cruise is convicted of a murder he hasn't committed yet, by a team of psychics called "precogs."
The precogs? They don't work. At all. We're told they predict the future but nothing they predict ever happens. If they actually predicted the future properly, they'd predict the people getting arrested, not committing murders.
In the entire movie, the only precog prediction that actually comes true exactly as they said involves a kid losing a balloon. Chinese fortune cookies have a higher success rate than these guys.
But maybe they're really more telepathic than precognitive, able to see what people's intentions are. Except they can't do that, either. The movie is set in motion by the premeditated murder ball coming out with Tom Cruise's character's name on it. But he hadn't planned the murder at all. The whole point of the movie is that he had no idea who he was going to kill.
The one time they do predict a murder that actually happens, they still manage to fuck it up. The loophole the movie's villain exploits is that if you commit a murder that looks identical to a previous murder, when the precogs' vision comes up they'll just think it was an echo and delete it. But that would only get rid of the image, there'd still be a new ball naming you as the murderer, which would be hard to explain. Seems like a flawed plan right? Well, it would be in any other movie.
Add that to the fact that Tom Cruise was able to continually get past the retina scanners at police headquarters by using the eyes he had when he first became a fugitive (they don't revoke your access when you get accused of murder? What, do they operate on the retina honor system?) and you have to wonder if they weren't just making shit up as they went along.