Biff Tanner getting his hands on the sports almanac

1980s Biff Tanner had time travel right. Instead of doing all that investing and sports betting, just find a patsy (preferably yourself) to do it for you, then head Back to the Future.

Quaid turning on the terraform artifact

In Total Recall, Arnold Schwarzenegger puts breathable air on Mars (or does he?). With this experience, we were surprised Arnold wasn't the first choice to star in Inception.

Desmond failing to push the button in a timely manner

This brought down Flight 815 to kick off LOST. Although after watching the pilot episode, it was totally obvious that the flight was ripped apart in the same way that every plane gets ripped apart by magic electromagnetism.

Fly in printer causing the execution of an innocent man

Brazil was filmed before people realized computers made it way easier to make giant errors.

Lister adopting a cat

In addition to a bunch of stuff involving humanoid cats, this kicks off Red Dwarf. It's amazing how many classic shows were started by small acts.

The light falling off

Making Jim Carrey's eponymous character realize he was in The Truman Show. We're glad he escaped, but now he should probably turn that into a negotiating ploy and cash in on a final season.

Dallas kissing Leelo

Thus convincing her to save the universe in The Fifth Element. Thank goodness he did it, otherwise one of those extraterrestrials would have had to come and kiss her.

Wall-E saving a plant

Leading to humanity's return to Earth and, well, humanity. Although robots are still in charge of the cleanup effort, so we're waiting for that to turn violent.

Donna Noble turning right instead of left

On the Doctor Who episode, "Turn Left," her simple act results in the death of tens of millions of people. For those of you who obsess over every tiny detail, let this be a reinforcement that you aren't obsessing enough.

Peter Parker getting bit by a spider

But if anyone asks who is involved in his lawsuit against the guys who were exhibiting the spider, he doesn't have awesome Spider Man powers, and is quite injured.

Neo taking the red pill

Hopping out of The Matrix, Neo proceeds to save the universe from computers. Or is that what happens? We kind of zoned out toward the end of Revolutions.

Adult John Connor giving Kyle Reese the photo of Sarah Connor

Thus kicking off the chain of events leading to the defeat of the Terminator. Or is it ending the chain of events? Time travel gets us confused.

The Observer distracting the alternate Walter

This makes the real Walter cross over universes, leading to what we know as Fringe. Interdimensional kidnappings are hard to process because you need a higher-dimensional being to preside over the hearing.

Dr. Smith choosing to board the ship

In the Lost in Space episode "The Time Merchant," the nefarious traitor is given a time-traveling chance to avoid boarding the rocket, which would kill all the more beloved characters. A more active-minded person might've disabled the rocket, but then Lost in Space would be erased from our minds.

Ralph leaving the bus full of children to search for help

Although he found the costume that made him The Greatest American Hero, he never gained any powers of field trip planning.

Nedry disabling the security system

Why does Jurassic Park even have a switch for "release all the dinosaurs?"

Otto Maddox's parents giving their money to a televangelist

Instead of paying tuition, he becomes a Repo Man, then aliens happen. Frankly, we didn't even need aliens to be entertained by Emilio Estevez hassling people.

Willie Tanner broadcasting an amateur radio signal

Following the signal, A.L.F. crashes into his garage. The radio signal must have been, "who wants to audition for a mediocre talk show?"

George McFly punching out Biff Tannen

In the later Back to the Futuress we never hear about "new and improved" George McFly's predisposition to solve matters with his fists.

Bilbo finding the One True Ring

In addition to this Hobbit, we also would have accepted, "Frodo keeping his fingers so soft and tasty."

The elderly people go night swimming

In Cocoon, all they wanted to do is perform a simple breaking-and-entering, not deal with an alien plot. They're retired!

Dr. McCoy accidentally injecting himself with too much cordrazine

In the Star Trek episode "City on the Edge of Forever," the doctor goes mad and starts screwing with the past. Nazi Germany wins World War II. We wonder if all this is listed on the cordrazine bottle under "side effects."

Stepping on a butterfly

The classic Ray Bradbury tale gets big-screen treatment in A Sound of Thunder.To avoid crushing things, always take your shoes off before traveling back in time; it's just like at the airport.