Captain Oblivious

Some characters are so completely insulated from the outside world that life, for them, is very different from life for others. This is extreme to the point that they literally have difficulty comprehending that life could be different for other people, and will work their everyday lives under the assumption that all people view life through the same lens that they do.

They can be given a rather rude awakening when, for one reason or another, a different character acts in such a way that the guy living in a bubble realizes that the world is a very, very different place from what he thought it was. Up until that point, they will always Fail A Spot Check if anything happens that conflicts with their world-view.

Often a good way to frame a Reasonable Authority Figure: The main reason they haven't acted so far is largely that they didn't realize what was going on.

See also I Thought Everyone Could Do That. This is the supertrope to Rich in Dollars Poor In Sense. A variation on No Social Skills. Not to be confused with Inspector Oblivious. Or Captain Obvious.

Film

 * Zoolander: Ben Stiller's character lives within the bubble of being "really really insanely good-looking". To the point where he and another male model are unable to figure out how to use a computer. They wind up recreating the monolith scene from Two Thousand A Space Odyssey, complete with banging on the sides of the monitor like apes and Also Sprach Zarathustra playing on the soundtrack.

Literature
"As I stood in my lonely bedroom at the hotel, trying to tie my white tie myself, it struck me for the first time that there must be whole squads of chappies in the world who had to get along without a man to look after them. I'd always thought of Jeeves as a kind of natural phenomenon; but, by Jove! of course, when you come to think of it, there must be quite a lot of fellows who have to press their own clothes themselves and haven't got anybody to bring them tea in the morning, and so on. It was rather a solemn thought, don't you know. I mean to say, ever since then I've been able to appreciate the frightful privations the poor have to stick."
 * Ken Follett's novel The Man from St. Petersburg has English Lord Stephen Walden's daughter Charlotte growing up in the 1900s. She has no idea what sex is, because she has grown up in a Gilded Cage.
 * Larry Niven's Ring World. In the original novel, Louis Wu decides that Teela Brown is incredibly naive about the dangers of real life because she was Born Lucky - so lucky that she never had to deal with any hardship.
 * Chris Fogle in The Pale King, during his wasteoid years. Even his life-changing event was the result of him going to the wrong classroom and experiencing something completely different from his own world view.
 * Lord Rust from Discworld is so self-assured he cannot comprehend that things are not exactly as he thinks they are. He doesn't even get a rude awakening - any information that conflicts with the way he sees things gets stopped at the door and sent on its way without ever making it to his brain.
 * Bertie from Jeeves and Wooster.

Live Action TV

 * In one episode of Thirty Rock, Liz discovers that her incredibly attractive boyfriend is oblivious to how far his attractiveness has got him in life. He can order ridiculous items like roast duck soaked in Fanta at restaurants, is under the hilariously inaccurate impression that he's a tennis prodigy, and most alarmingly, somehow became a medical doctor in spite of not even knowing what the Heimlich maneuver is.
 * The Prince Regent from Black Adder.
 * The Hendrys in The Day After have no idea that the world is hurtling towards nuclear war. Even with their TV loudly blaring newscasts and EBS warnings they're completely oblivious to the danger - going so far as to discuss the state of the fields over the two-tone alert - until an ICBM launches in the next field. Their * frantic attempts to flee come too late when they're engulfed by a fireball and incinerated.
 * The Tick in the Tick

Religion

 * This is The Buddha's Origin Story. He was prophesied to either be a great king, or a sage who rejected the world. His father preferred the first option, so he had him grow up in a bubble of perfect happiness, building a world he would never want to reject..

Video Games

 * Luke in Tales of the Abyss. He eventually gets kicked out of his bubble very, very harshly.

Web Comics
"Mace Windu: Why doesn't anyone ever tell me about stuff??"
 * Mace Windu, in Darths and Droids. A Running Gag is he is never aware of what is going on, despite his position of power.

Western Animation

 * The Earth King in Avatar: The Last Airbender. So much so that he didn't realize his country was at war for an entire century.

Real Life

 * Considering what happened afterward, it's rather astounding that the summoning of the Estates General directly before the French Revolution was actually the aristocracy's idea. They apparently genuinely did not realize how much the commoner classes in France hated them. This even though from a modern perspective the peasantry's reaction to having a democratic legislative body was fairly predictable. Consider the fact that for centuries French nobles lived above the law, controlled the government, and shouldered virtually no nationalist responsibility. Meanwhile the peasants had to lay down their income and lives in order to finance and staff France's many eighteenth century wars, most of which didn't even accomplish anything.
 * The third estate of the Estates General, theoretically the commoners, was probably the most loathed by the peasantry of all. It consisted of people that would now be considered the middle class and they were actually the most insistent on shifting as much of the tax burden as possible onto the peasantry. Especially since said middle class included the tax farmers; people who had to deliver a certain amount of money to the state (the technical term was "Abonnement fiscal") and were allowed to take it from the peasants in return. Many of those became pretty rich... The French nobles were for centuries more consistently siding with the peasantry than the supposed representatives of the common people. The nobles didn't reach the level of decadence attributed to them until a few decades before the revolution.
 * Hindsight is a beautiful thing...