When he's gone, Claire opines that people will ask questions about the crash, but Bennet informs her she's mistaken, and no one's going to know a thing. An ominous whistling accompanies this declaration, and when Claire, dread in her voice, asks what he did, he answers by looking to the sky, from which a missile appears and blows up the plane. I hate to argue with such a dramatic display, but if someone were going to ask questions about a mysterious plane's mysterious landing, I'm not sure an ensuing mysterious explosion would get them to go about their day like nothing happened. But I could be overestimating people's average intelligence and curiosity.
"Bless them, they'll go to any lengths to ignore magic, even if it's staring them in the face..."
— Arthur Weasley, Harry Potter and the Chamber of Secrets
"We're ostriches, and the whole world is sand. Newbies who are just learning about the world of wizards and the unpleasant side of the supernatural always think there's this huge conspiracy to hide it from everyone. There isn't. There's no need for one, beyond preventing actual parades down Main Street. Hell's bells, from where I'm standing, it's a miracle anyone ever notices."
— Harry Dresden, The Dresden Files
"Picnic on the head of the Sphinx, hang out with the minute hand on Big Ben as if you were Mary Poppins... and, here's the thing: Nobody notices."
Tiana: Stella just talked to me! A dog! Just talked to me!
Naveen: You know, if you are going to let every little thing bother you, it's going to be a long night.
There's a phantom in the basement, the janitor's a spy, the principal's a rhino and no-one's asking why! Dinosaurs are everywhere, a twister's in the sky! It's just another day at Flying Rhino Junior High!
You thought I'd say "HOW THE FUCK DID THAT HAPPEN?!?"...In reality, it didn't.
Mickey Smith: (after the Doctor explains why the TARDIS resembles a Police Box) But that's what I meant, there's no police boxes any more, so doesn't it get noticed?
The Doctor: Ricky, let me tell you something about the human race. You put a mysterious blue box slap-bang in the middle of town, what do they do? Walk past it. Now stop your nagging. Let's go and explore.
— Doctor Who, "Boom Town"
It was true that normal people couldn't hear Gaspode speak, because dogs don't speak. It's a well known fact. It's well known at the organic level, like a lot of other well-known facts which overrule the observation of the senses. This is because if people went around noticing everything that was going on all the time, no-one would ever get anything done. Besides, almost all dogs don't talk. Ones that do are merely a statistical error, and can therefore be ignored.
"The technology involved in making something properly invisible is so mind-bogglingly complex that 999,999,999 times out of a billion it's simpler just to take the thing away and do without it... The 'Somebody Else's Problem field' is much simpler, more effective, and "can be run for over a hundred years on a single torch battery."
People would enter the elevator every once in a while.
They found a six-year-old boy sticking a screwdriver into a CD player and a stuffed tiger with a magazine sitting in the corner.
They chose not to do anything about it.
— Calvin and Hobbes: The Series, "Department Store Horrors"
"People rationalize what they can and forget what they can't."
— Rupert Giles, Buffy the Vampire Slayer
Ah yes, "Reapers". The immortal race of sentient starships allegedly waiting in dark space. We have dismissed that claim.
— Turian councillor, Mass Effect 2
C-Sec customs: After the Geth attack there was a review of security protocol. A few minor changes were made to reduce the risk of Geth infiltration. We apologise for the inconvenience.
Legion (a Geth): Geth do not infiltrate.
C-Sec customs: You should leave your personal synthetic assistant at home, they're not allowed in shuttles any more.
Legion: Geth do not intentionally infiltrate.